godan verb (-su), transitive verb
leave undone; neglect; break (a promise); stand up
Colloquial verb for deliberately failing to do something one should do, such as skipping a task, breaking an appointment, or standing someone up. Often carries a casual, slightly irresponsible tone.
彼は約束をすっぽかして、来なかった。
He broke his promise and didn't come.
I neglected my homework and went out to play.
デートをすっぽかされた。
I was stood up on a date.