Strong's 1492 (εἴδω)

be aware, behold, X can (+ not tell), consider, (have) know(-ledge), look (on), perceive, see, be sure, tell, understand, wish, wot

used only in certain past tenses, the others being borrowed from the equivalent G3700 (ὀπτάνομαι) and G3708 (ὁράω); properly, to see (literally or figuratively); by implication, (in the perfect tense only) to know

a primary verb;