have a shower
1. Literally, to clean oneself in a shower. I got really sweaty working out in the back yard, so I'm going to have a shower before lunch. I prefer to have showers, but having a bath now and then is nice, too.
2. To bathe in general, not necessarily in a shower. There are a few people in my office who could stand to have a shower a bit more regularly. You might have better luck on your dates if you had a shower every once in a while!