Synonyms and related words :
amplify, back, be tough, beef up, brace, brace up, buttress, case harden, charge, clot, coagulate, confirm, congeal, crystallize, electrify, endure, energize, fortify, galvanize, generate, gird, hang tough, harden, invigorate, jell, loop in, nerve, plug in, prop, refresh, reinforce, reinvigorate, restrengthen, rigidify, screw up, set, shock, shore up, short, short-circuit, solidify, steel, step down, step up, strengthen, support, sustain, switch off, switch on, tauten, temper, tense, thicken, tighten, toughen, trice up, turn off, turn on, undergird