Arabic has had a great influence on other languages, especially in vocabulary. The influence of Arabic has been most profound in those countries dominated by Islam or Islamic power. Arabic is a major source of vocabulary for languages as diverse as Berber, Kurdish, Persian, Swahili, Urdu, Hindi (especially the spoken variety), Turkish, Malay, and Indonesian, as well as other languages in countries where these languages are spoken. For example the Arabic word for book /kita:b/ is used in all the languages listed, apart from Malay and Indonesian (where it specifically means "religious book"). Other languages such as Maltese and Kinubi derive from Arabic, rather than merely borrowing vocabulary.
The terms borrowed range from religious terminology (like Berber taẓallit "prayer" < salat), academic terms (like Uyghur mentiq "logic"), economic items (like English "sugar") to everyday conjunctions (like Urdu lekin "but".) Most Berber varieties (such as Kabyle), along with Swahili, borrow some numbers from Arabic. Most religious terms used by Muslims around the world are direct borrowings from Arabic, such as salat 'prayer' and imam 'prayer leader'. In languages not directly in contact with the Arab world, Arabic loanwords are often mediated by other languages rather than being transferred directly from Arabic; for example, most Arabic loanwords in Urdu entered through Persian, and many older Arabic loanwords in Hausa were borrowed from Kanuri.
Outside the Islamic world, there are more limited borrowings from Arabic, usually to denote vegetables and other articles in commerce, such as "aubergine" and "alcohol". Arabic influence is particularly pervasive in Spanish and Portuguese, where it often supplies place names, as well as the placeholder fulano ("so and so").
Like other European languages, English contains many words derived from Arabic, often through other European languages, especially Spanish and Italian. Among them is every-day vocabulary like "sugar" (sukkar), "cotton" (quṭn) or "magazine" (). More recognizable are words like "algebra", "alcohol", "alchemy", "alkali", "cypher" and "zenith" (see list of English words of Arabic origin). These words are often productive sources of derivatives, such as "algebraic", "alcoholic", "alcoholism", and "decipher".
A more indirect form of influence is the use of certain Latinate words in an unclassical sense, derived from their use in Latin translations of medieval Arabic philosophical works (e.g. those of Averroes), which entered the scholastic vocabulary and later came into normal use in modern languages. Examples are "information" to mean the imparting or acquisition of knowledge (Arabic taşawwur, mental impression or representation, from a root meaning "form") and "intention" (Arabic ma'na, meaning). These words may almost be regarded as calques.
Between the 9th and the 15th centuries Portuguese acquired about 1000 words from Arabic by influence of Moorish Iberia. However, following the expulsion of the Arabs from Portugal during the Reconquista, the native population who spoke the Lusitanian-Mozarabic, which is believed to have been very similar to the Galician-Portuguese, kept many Arabic words from Mozarabic. Words of Arabic origin are often recognizable by the initial Arabic article a(l)-, and include many common words such as aldeia "village" from الضيعة, alface "lettuce" from الخس alkhass, armazém "warehouse" from المخزن almakhzan, and azeite "olive oil" from الزيت azzait. From Arabic came also the grammatically peculiar word oxalá "God willing". The Algarve is al-gharb, the west. The frequency of Arabic toponyms increases as one travels south in the country.
The Spanish language has been heavily influenced by Arabic as a result of the Islamic presence in the Iberian peninsula between AD 711 and AD 1492. Modern day Spanish (or Castilian) first appeared in the small Christian Kingdom of Castile in Northern Spain during this period of Islamic domination over most of the Iberian peninsula. As a result, the language was influenced by Andalusi Arabic practically from its inception. Nevertheless, Arabic imprint on the language increased as the Kingdom of Castile expanded into Muslim lands where the Castilian language had never been spoken and as arabized Christians (Mozarabs) from Al Andalus emigrated northwards during times of sectarian violence in Muslim lands. In most of Al Andalus, Arabic was used among the local élites and local Arabic-influenced Romance dialects, known collectively as Mozarabic were generally used as the vernacular language. Only the kingdom of Granada, under the Nasrid dynasty was totally arabized after many centuries of Muslim rule.
Modern Spanish is thus a mixture of Old Castilian and the Mozarabic dialects which it absorbed. This fusion explains why Spanish has, in many cases, both Latin and Arabic derived words of the same meaning. For example, aceituna and oliva (olive), alacrán and escorpión (scorpion), jaqueca and migraña (headache) or alcancía and hucha (piggy bank). The imprint of Mozarabic and Arabic is evidently more noticeable in the dialects of Castilian Spanish spoken in southern Spain than in northern Spain.
It is estimated that there are over four thousand Arabic loanwords in the Spanish language (including derivations) and well over one thousand Arabic roots. A majority of these are nouns, with a more limited number of verbs, adjectives, adverbs and prepositions, thus not substantially changing the grammar or basic structure of the language. Examples include berengena (aubergine, from bedinjan), aceite (oil, from az-zayt), and alcalde (mayor, from al-qadi).
There are hundreds if not thousands of place names and names of geographical features derived from Arabic in Spain. Examples include place names such as Alcazar and Alhambra, and the Guadalquivir, from wadi l-kabir, 'the great river'. Toponyms derived from Arabic are common in all of Spain (including much of the North of the country) except for those regions which never came under Muslim rule or where it was particularly short-lived. These regions include Galicia and the Northern coast (Asturias, Cantabria and the Basque country) as well as most of Catalonia. Regions where place names of Arabic origin are particularly common are the Eastern Coast (Valencia and Murcia) and the region of Andalusia.
Those toponyms which maintained their pre-Islamic name during the Muslim period were generally Arabized and the mark of the old Arabic pronunciation is noticeable in their modern names: e.g. Caesarea Augusta - سرقسطة Saraqusţah - Zaragoza.
The suffix í. Arabic has a very common type of adjective, known as the nisbi or relationship adjective, which is formed by adding the suffix -ī (masc.) o ية -iyya (fem.) to a noun. This has given Spanish the suffix -í (both masc. and fem.), creating adjectives from nouns which indicate relationship or belonging. Examples are Marbellí, Ceutí, Maghrebí, Zaragozí, Andalusí or Alfonsí. (Catalan also has this suffix, as in the word Llemosí (Limousin), but this appears to be the Catalan equivalent of the Spanish -ín, French -in and Italian -ino rather than an Arabic borrowing.)
Expressions. A number of expressions in Spanish have been translated or adapted from their Arabic equivalent. Examples would be si Dios quiere, que Dios guarde or bendita sea la madre que te pario. The generally accepted etymology of hidalgo 'nobleman' — Old Spanish fijo d'algo — is composed of Latin roots (cf. Modern Spanish hijo 'son' + algo 'something'), but is considered a calque of an Arabic phrase using ibn 'son' to mean simply 'person characterized by (the idea expressed by the following noun)'. In Old Spanish, algo could mean 'wealth, property'.
Following the adoption of Islam c. 950 by the Kara-Khanid Khanate and the Seljuq Turks, regarded as the cultural ancestors of the Ottomans, the administrative language of these states acquired a rather large collection of loanwords from Arabic, as well as Persian. During the course of over six hundred years of the Ottoman Empire (c. 1299–1922), the literary and official language of the empire was a mixture of Turkish, Persian and Arabic, which differed considerably from everyday spoken Turkish of the time, and is termed Ottoman Turkish.
After the foundation of the Republic of Turkey, and following the script reform, the Turkish Language Association (TDK) was established under the patronage of Mustafa Kemal Atatürk in 1932, with the aim of conducting research on Turkish. One of the tasks of the newly established association was to initiate a language reform to replace loanwords of Arabic and Persian origin with Turkish equivalents. By banning the usage of replaced loanwords in the press, the association succeeded in removing several hundred foreign words from the language, thus diminishing but by no means erasing the Arabic influence on Turkish.
Dozens of Arabic words occur in Interlingua, frequently because their co-occurrence in such languages as English, French, Italian, Spanish, and Portuguese can be used to verify their internationality. Many of these words entered Interlingua's vocabulary through Spanish and Portuguese. Arabic words in Interlingua include "algebra", "alcohol", "cifra" (cypher), "magazin", "sucro" (sugar), "zenit", and "zero".