From Latin 'cognōscere' (to get to know), built on the PIE root *ǵneh₃- (to know) — the same root behind English 'know,' Greek 'gnosis,' and the disguise sense of 'incognito.'
Relating to or involving the mental processes of perception, memory, judgment, and reasoning
Cognitive entered English in the 1580s from Medieval Latin 'cognitivus,' derived from Latin 'cognitus,' the past participle of 'cognōscere' (to get to know, to recognize). This verb is a compound of 'co-' (together, with) and 'gnōscere' (older form 'nōscere'), meaning 'to know,' from the Proto-Indo-European root *ǵneh₃- (to know). This PIE root is one of the most productive in the Indo-European family, yielding Greek 'gnōsis' (knowledge), Sanskrit
The word 'cognitive' existed in English for nearly 400 years before it became common. It appeared in 1586 but was rarely used until the 1950s 'cognitive revolution' in psychology, when researchers like Noam Chomsky and George Miller challenged behaviorism and argued that studying internal mental processes was both possible and necessary.