godan verb (-su)
trample to death; kill by stepping on
Used for killing small creatures or, figuratively, crushing something underfoot. Literal and sometimes metaphorical.
うっかりして蟻を踏み殺してしまった。
I accidentally stepped on an ant and killed it.
彼はその小さな虫を踏み殺した。
He trampled the small bug to death.