Find definitions of Spanish words at dictionary.reverso.net and WordReference.com, or use a smartphone app, such as Bravolol's free Spanish English Dictionary & Translator. Appcrawlr.com features other suitable apps, including free apps for various smartphone types.
The main page at Reverso features a tool to look up definitions of Spanish words and display them in English or Spanish. You can use tools on this website to translate a word or phrase from Spanish to English or other languages, and vice versa, or to conjugate Spanish verbs. The tool also functions as a thesaurus to provide synonyms for Spanish words.
At WordReference.com, type a Spanish word into the box on the main page, and then click Spanish: Definition to display the definition in Spanish or click Spanish-English to display various translations in English. On the definition page, click the audio icon to listen to the word's Spanish pronunciation. This website also features a Spanish verb conjugator tool.
To find a suitable smartphone app at Appcrawlr, type "Spanish dictionary" in the search box near the top of the main page, and then select your device type on the dropdown menu and click Go. Click the Free checkbox in the list of search options to display only apps that are available free of charge. Click a listing, and then click the Download button to redirect to a page where you can download the app.