Where does “potrhlík” come from?

potrhlík (Czech) comes from Czech potrhlý, from Czech potrhat, from Czech po-, from Old Czech [[po-]], [[pó-]].

potrhlík (Czech): crackpot

Definitions

Step	Language	Word	Meaning
1	Czech	potrhlý	—
2	Czech	potrhat	—
3	Czech	po-	Perfective aspect, as in "požádat" ask; After, as...
4	Old Czech	[[po-]], [[pó-]]	—

potrhlík — Etymology, Origin & Word History | Etymology Explorer