- The sleeve of a shirt.
- The state of wearing no coat, jacket, or other outer garment over one's shirt: dined in shirtsleeves; balmy weather that had them down to their shirtsleeves.
- Dressed without a coat: shirtsleeve spectators; a shirtsleeved orchestra.
- Calling for the removal of a coat or jacket; not requiring a coat or jacket for comfort: shirtsleeve weather; a shirtsleeves picnic.
- Marked by informality or straightforwardness: shirtsleeve politics; a shirtsleeves conference.