1. To drive or tighten a screw or similar fastener (into something). A noun or pronoun can be used between "screw" and "in." You forgot to screw in these last two screws, so the whole thing fell apart! We just need to screw this last one in the bed frame, and it will be finished.

2. To affix or secure something (into or onto something) with screws or in the manner of a screw. A noun or pronoun can be used between "screw" and "in." Remember to screw in the safety latch when you're reassembling the washing machine. We should start getting a better signal once I screw the new antenna in on the roof.