verb/pe.te ply o k(ə) sɔ̃ ky/
to think one's shit doesn't stink; to think the sun shines out of one's arse; to think one is the shit; to think one is the business; to think one is hot shit (to be full of oneself)
Synonyms: ne pas se prendre pour de la merde, péter plus haut que le trou, se croire sorti de la cuisse de Jupiter, se croire le premier moutardier du pape
Literally, “to fart higher than one's ass”.