1. Make strong or stronger
   "This exercise will strengthen your upper body"; "strengthen the relations between the two countries"
   - beef up, fortify 
2. Gain strength
   "His body strengthened" 
3. Give a healthy elasticity to
   - tone, tone up

Derived forms: strengthened, strengthening, strengthens

See also: strengthener, strengthening

Type of: alter, change, exercise, modify, work out

Antonym: weaken

• miller
• miller's-thumb
• millerite
• millesimal
• millet
• millettia
• milli-
• milliammeter
• milliampere
• milliard
• milliary
• millibar
• millicurie
• millidegree
• milliequivalent
• millifarad
• milligram
• millihenry
• Millikan
• milliliter
• millilitre
• millime
• millimeter
• millimeter of mercury
• millimetre