The most comprehensive way to find any Spanish adjective is to purchase an English-Spanish dictionary, according to Intro2Spanish.com. However, for a free online option, the website offers a master list of common Spanish adjectives in alphabetical order, and their English translations as a resource for English speakers learning Spanish.
The list includes adjectives in singular masculine form, singular feminine form, plural all-male or mixed-gender form, and plural all-female form. The gender and number of the adjective are determined by the gender and number of the noun which the adjective describes. All adjectives on the list include English translations, some of which list synonyms. For example, the Spanish adjective "baboso" is translated to English as "moronic," "drooling," "slavering," and "idiotic" on Intro2Spanish.com