a word or a group of words, usually functioning as an adjective or noun, that is used in the predicate following a copula and describes or is identified with the subject of the sentence, as sleepy in The travelers became sleepy.
Origin of subject complement
First recorded in 1935–40
Also called subjective complement.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019