Make strong or stronger:
— This exercise will strengthen your upper body.
— Strengthen the relations between the two countries.

synonyms: beef up, fortify.

Roget 159: be strong etc. adj., be stronger; overmatch.    render strong etc. adj.; give strength etc. n.; strengthen, invigorate, brace, nerve, fortify, sustain, harden, case harden, steel, gird; screw up, wind up, set up; gird up one's loins, brace up one's loins; recruit, set on one's legs; vivify; refresh etc. 689; refect^†; reinforce, reenforce etc. (restore) 660.    ... show more

Roget 35: increase, augment, add to, enlarge; dilate etc. (expand) 194; grow, wax, get ahead.    gain strength; advance; run up, shoot up; rise; ascend etc. 305; sprout etc. 194.    aggrandize; raise, exalt; deepen, heighten; strengthen; intensify, enhance, magnify, redouble; aggravate, exaggerate; exasperate, exacerbate; add fuel to the flame, oleum addere camino [Lat.], superadd etc. (add) 37; spread etc. (disperse) 73.    ... show more

Roget 157: be powerful etc. adj.; gain power etc. n.. belong to, pertain to; lie in one's power, be in one's power; can, be able.    give power, confer power, exercise power etc. n.; empower, enable, invest; indue^†, endue; endow, arm; strengthen etc. 159; compel etc. 744.    ... show more

Dutch: bezielen, kracht geven, tot leven wekken, stalen, sterken, versterken, verstevigen

Gain strength.

Give a healthy elasticity to.

synonyms: tone, tone up.