gno/cogn

know

Spelled gno, gnos, cogn · gignoskein (Greek) / cognoscere (Latin), cognates of *gno- 'know'

Greek gignoskein and Latin cognoscere mean know: a prognosis predicts; someone cognizant knows, while someone incognito keeps their identity unknown.

Words built from it

prognosis — A prediction of how a situation or illness will develop.
Greek pro- (before) + gnosis (knowing), from gignoskein (know) → prognosis (foreknowledge)
agnostic — Someone who holds that whether God exists is unknown or unknowable.
Greek a- (not) + gnostos (known), from gignoskein (know) → English agnostic
cognizant — Aware of something.
Latin cognoscere (know) → Old French conoissance (knowledge) → English cognizance + -ant
incognito — With one's identity concealed.
Latin in- (not) + cognitus (known), from cognoscere (know) → Italian incognito → English incognito
diagnosis — Identification of an illness or problem by examining its signs.
Greek dia- (apart) + gnosis (knowing), from gignoskein (know) → diagnosis (distinguishing)
recognition — Identification of someone or something previously encountered.
Latin re- (again) + cognoscere (know) → recognoscere (know again) → recognitio → English recognition
cognition — The mental process of gaining knowledge and understanding.
Latin cognoscere (know) → cognitio (knowing, knowledge) → English cognition

cognate — Latin cognatus combines co- (together) with gnatus (born). Its cogn- concerns shared birth or origin, not knowing.