Real Dictionary

adjective
countable noun: An adjective is a word such as ' big', ' dead', or ' financial' that describes a person or thing, or gives extra information about them. Adjectives usually come before nouns or after link verbs.

adjective in American English
any of a class of words used to modify a noun or other substantive, as by describing qualities of the entity denoted, stating its limits or quantity, or distinguishing it from others (Ex.: good, every, Aegean)
of an adjective
noun: any member of a class of words that in many languages are distinguished in form, as partly in English by having comparative and superlative endings, or by functioning as modifiers of nouns, as good, wise, perfect

adjective in British English
noun: a word imputing a characteristic to a noun or pronoun