Verb: strengthen strengk-thun
- Make strong or stronger
"strengthen the relations between the two countries"; "This exercise will strengthen your upper body";
- beef up [informal], fortify
- Gain strength
"His body strengthened";
- toughen
- Improve muscle strength and firmness through exercise
"Let's strengthen our muscles";
- tone, tone up
Derived forms: strengthens, strengthened, strengthening
Type of: alter, change, exercise, modify, work out
Antonym: weaken