すっぽかす
suppokasu

Godan Verb (su)

1. to leave (something) undone; to neglect (a duty, task, etc.); to break (a promise, appointment, etc.); to stand (someone) up

Transitive
Colloquial
上司 じょうしとの約束 やくそくをすっぽかした。
jōshitono yakusokuo suppokashita.
I skipped out on my appointment with my boss.