to become thinner; to lose weight. You have really slimmed down a lot since I last saw you. I need to eat less so I can slim down. He slimmed down quite a bit after he had his health problem.
to cause someone to lose weight. They started to slim her down in the hospital, but she gained the weight back as soon as she got out. The dietitian slimmed down all the patients under his care.
A small amount left after others have taken a share. For example, After each of the children took what they wanted of Mother's things, it was slim pickings for the rest of the family . This expression alludes to animals devouring a carcass. [Early 1600s]