"word used to qualify, limit, or define a noun or noun-like part of speech," late 14c., short for noun adjective, from Old French adjectif (14c.), from Latin adjectivum "that is added to (the noun)," neuter of adjectivus "added," past participle of adicere "throw to, fling at, throw or place (a thing) near," especially "add in addition, add by way of increase," from ad "to" (see ad-) + combining form of iacere "to throw" (from PIE root *ye- "to throw, impel"). In Britain from at least 1851 the word often was a euphemism for the taboo adjective bloody.
They ... slept until it was cool enough to go out with their 'Towny,' whose vocabulary contained less than six hundred words, and the Adjective. [Kipling, "Soldiers Three," 1888]