1. To trim something to the correct or desired shape or appearance. A noun or pronoun is used between "trim" and "up." I asked our gardener to trim up the hedges. The window frame is not fitting quite right in the wall, so I'll need to trim it up a bit. You need to trim your beard up a bit.
2. To give someone a minor haircut. A noun or pronoun is used between "trim" and "up." I'm not looking for any fancy new hairstyle. Just trim me up a little. I want to get trimmed up before my big meeting tomorrow.
3. To decorate or adorn something to the desired degree. A noun or pronoun is used between "trim" and "up." We're going to trim up the Christmas tree on Saturday. My job is to trim the window displays up at the start of each season.
4. To put up decorations for Christmas. Primarily heard in UK. People shouldn't be allowed to start trimming up until at least the middle of November!
5. In sailing, to cause the fore of the vessel to raise up by shifting its balance towards the aft. Primarily heard in UK. You'll need to trim up a bit before you start slowing down, otherwise the nose might dip into the water.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.