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.
pro- (before) + gnos (know) + -is (process)
agnostic — Someone who holds that whether God exists is unknown or unknowable.
a- (not) + gnos (know) + -tic (relating to)
cognizant — Aware of something.
cogn (know) + -ant (being)
incognito — With one's identity concealed.
in- (not) + cogn (know)
diagnosis — Identification of an illness or problem by examining its signs.
dia- (apart) + gnos (know) + -is (process)
recognition — Identification of someone or something previously encountered.
re- (again) + cogn (know) + -ition (process)
cognition — The mental process of gaining knowledge and understanding.
cogn (know) + -ition (process)

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