THESAURUS
redouble
accelerate, aggravate, beef up, blow up, come again, complicate, concentrate, condense, consolidate, copy, deepen, ditto, do a repeat, do again, do over, double, dupe, duplicate, echo, enhance, exacerbate, exaggerate, geminate, heat up, heighten, hop up, hot up, imitate, ingeminate, intensify, jazz up, key up, magnify, make complex, mount, multiply by two, parrot, plagiarize, quote, ramify, redo, reduplicate, reecho, regurgitate, reincarnate, reinforce, renew, repeat, replicate, reproduce, revive, rise, rouse, say again, sharpen, soup up, step up, strengthen, triple, twin, whet
ROGET THESAURUS
redouble
Increase
VB
increase, augment, add to, enlarge, dilate, grow, wax, get ahead, gain strength, advance, run up, shoot up, rise, ascend, sprout, aggrandize, raise, exalt, deepen, heighten, strengthen, intensify, enhance, magnify,
redouble, aggravate, exaggerate, exasperate, exacerbate, add fuel to the flame, oleum addere camino, superadd, spread.
Duplication
VB
double,
redouble, duplicate, reduplicate, geminate, repeat, renew.
Repetition
VB
repeat, iterate, reiterate, reproduce, echo, reecho, drum, harp upon, battologize, hammer,
redouble, recur, revert, return, reappear, recurse, renew, rehearse, do over again, say over again, ring the changes on, harp on the same string, din in the ear, drum in the ear, conjugate in all its moods tenses and inflexions, begin again, go over the same ground, go the same round, never hear the last of, resume, return to, recapitulate, reword.