Also found in: Dictionary, Thesaurus.
1. To become leaner, tighter, and more muscular. I really want to tone up before my wedding this August.
2. To cause someone or some body part to become leaner, tighter, and more muscular. In this usage, a noun or pronoun can be used between "tone" and "up." Our program promises to tone you up in just six weeks. Cycling to work each morning has gone a long way toward toning up my legs.
tone someone or something up
to make someone or something stronger or more fit, muscularly. I suggested an exercise that would tone him up and make him feel better. The exercises toned up his tummy muscles. I need to get busy and tone myself up.
1. To make something firmer or stronger: Walking to work has toned up my legs. I toned my stomach up by doing sit-ups every day.
2. To become firmer or stronger: My body has really toned up since I started this exercise program.