I swear I didn’t do anything. I was just running some errands there for my dad this morning.
Remember 済む and how it means "to come to an end." This is like that, but slightly different. This is to finish or to settle, because this is when you're doing the coming to an end action. You can remember this because you're coming in to finish the score uno mas (ます) time. This is the last time.
The reading is the same as the one you learned with 済む, so if you know that you'll be able to finish this vocab.