From Latin 'cognoscere' (to get to know), from PIE *gneh3- — same root as 'know,' 'gnosis,' and Sanskrit 'jnana.'
The mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.
From Latin 'cognitiōnem' (accusative of 'cognitiō'), meaning 'a getting to know, acquaintance, knowledge,' from the past participle stem of 'cognōscere' (to get to know, to recognize), itself a compound of 'co-' (together) and 'gnōscere,' an older form of 'nōscere' (to come to know). The underlying root is PIE *ǵneh₃- (to know), one of the most productive roots in Indo-European, which also gave rise to English 'know,' Greek 'gnōsis,' and Sanskrit 'jñāna.' Key roots: cognōscere (Latin: "to get to know, to recognize"), *ǵneh₃- (Proto-Indo-European: "to know").
The word 'cognition' shares its deepest root with the everyday English word 'know.' Both descend from PIE *ǵneh₃-, but 'know' took the Germanic path (Old English 'cnāwan') while 'cognition' traveled through Latin — making them doublets separated by thousands of years and thousands of miles of migration.