the enantiodromic process sometimes changes the meaning of words from one thing to its opposite over time; thus prestigious originally meant cheating, deluding, deceitful; deceptive, illusory (cf. prestidigitation), and now means having influence or reputation derived from previous character, achievements, or associations. (the link is magic, glamour). some have disdain for the big word and call these words, where both senses still survive, Janus words. you can find lists of them online, but many of them are highly questionable (which is to say, they're a reach).

on the other hand, cleave and cleave are not conjugates but homonyms.