'Recognize' is Latin for 'know again' — from 're-' (again) + 'cognoscere' (to get to know).
To identify someone or something from having encountered them before; to acknowledge the existence, validity, or legality of something.
From Latin "recognōscere" (to know again, recall to mind, examine), a compound of "re-" (again, back) and "cognōscere" (to get to know, learn). The base verb "cognōscere" itself combines "co-" (together, an intensifier from PIE *ḱom, meaning with or together) and "gnōscere" (to come to know), from the PIE root *ǵneh₃- (to know). This prolific root produced an extraordinary family: Latin "nōscere/gnōscere" (to know), Greek "gignṓskō" (I know), Sanskrit "jānā́ti" (he knows), Old
The legal term 'recognizance' (a bond by which a person pledges to appear in court) comes from the same word. In medieval law, to 'recognize' a debt or obligation was to formally acknowledge it before a court — a sense that survives in phrases like 'the chair recognizes the senator.' Military 'reconnaissance' is the same word borrowed again from French