From Greek 'gnṓsis' (knowledge), from PIE *ǵneh₃- (to know) — the same root behind English 'know' and 'diagnosis.'
Knowledge of spiritual mysteries; esoteric or intuitive knowledge, especially that claimed by the ancient Gnostics.
From Greek γνῶσις (gnōsis, knowledge, inquiry, especially spiritual or esoteric knowledge), from γιγνώσκω (gignṓskō, I know, I perceive, I come to know), from PIE *ǵneh₃- (to know, to recognise). This is among the most productive roots in Indo-European, generating knowledge-words across every major branch: Latin 'gnōscere/nōscere' (to come to know) → 'cognition,' 'recognise,' 'noble' (known, notable); Sanskrit ज्ञान (jñāna, knowledge) — the root of Jnana yoga; Old English 'cnāwan' (to know, perceive) → Modern English 'know;' Old Irish 'gnáth' (known, customary); Old Church Slavonic 'znati' (to know); Lithuanian 'žinoti' (to know). The Greek γνῶσις entered English primarily through the early Christian context: Gnosticism (2nd century CE) was a diverse
Greek 'gnosis' and English 'know' are cognates from PIE *ǵneh₃-. The initial 'gn-' cluster, which Greek preserved, was simplified to 'kn-' in Germanic (later losing the 'k' in pronunciation but keeping it in spelling). The 'silent k' in 'know,' 'knee,' and 'knight' was once pronounced — making