1. (adv.) Two times; once and again.

2. (adv.) Doubly; in twofold quantity or degree; as, twice the sum; he is twice as fortunate as his neighbor.

Doppelganger Janus-like Machiavellian Photostat Xerox aberrancy aberration accelerate act for actual thing agent aggravate alternate alternative ambidextrous ambiguous amplify analogy artful at full speed at once augment average avoid backup beef up beg bend bias bifacial bifold biform bifurcated bilateral bilk binary binate biparous bipartisan bipartite bisect bivalent blow up branching off briskly carbon copy change change places with changeling circuitousness circumvent clone co-walker come again come back come home companion comparison complicate concentrate condense conduplicate consolidate coordinate copy corner counterfeit counterpart coupled crafty crease creasing crimp crisp crook crooked crowd out cunning curve cut out dead ringer deceitful declination deepen deflection departure deputy detour deviance deviancy deviation deviousness dichotomous digression discursion dishonest disomatous displace ditch ditto divagation divarication divergence diversion do a repeat do again do over dog-ear dogleg double back double for double over double-dealing double-faced double-minded double-tongued doubled doubleganger doublehearted doubling drift drifting duadic dual dualistic dub duck dummy dupe duple duplex duplicate duplicated duplication duplicature duplicitous dyadic echo effigy elude enfold enhance enlarge equal equivalent errantry ersatz escape eschew etheric double evade exacerbate exact counterpart exact likeness exaggerate exchange excursion excursus exorbitation facsimile faithless fake FALSE false-principled falsehearted fellow fetch fill in for fill-in flection flexure flounce flute fold fold over frill gather geminate geminated get around get away from get out of ghost ghostwrite ghostwriter go back go home hairpin heat up hectograph heighten homograph homonym homophone hop up hot up hypocritical icon idem identical identical same idol image imitate imitation immediately increase indirection infold ingeminate insincere intensify interfold jazz up key up lap over lapel lappet likeness living image living picture locum tenens magnify make complex makeshift manifold match matched mate metaphor metonymy microcopy microfilm middle mimeo mimeograph miniature mirror image mirroring model multigraph multiply by two next best thing no other none other obliquity on the run paired parrot pererration perfidious personnel phony photograph