godan verb (-su), transitive verb
neglect; leave undone; leave alone
Casual, often negative nuance: leaving something or someone unattended, unfinished, or uncared for. Implies a lack of responsibility or attention.
宿題をほったらかして遊びに行った。
I left my homework undone and went out to play.
彼は部屋をほったらかしにして出かけた。
He went out, leaving his room a mess.
あの子をほったらかしておくのは心配だ。
I'm worried about leaving that child unattended.