The Collaborative International Dictionary of English v.0.48:

Reactionary \Re*ac"tion*a*ry\ (-[asl]*r[y^]), a.
   Being, causing, or favoring reaction; as, reactionary
   movements.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Reactionary \Re*ac"tion*a*ry\, n.; pl. Reactionaries
   (-r[i^]z).
   One who favors reaction, or seeks to undo political progress
   or revolution.
   [1913 Webster]

WordNet (r) 3.0 (2006):

reactionary
    adj 1: extremely conservative [syn: reactionary,
           reactionist, far-right]
    n 1: an extreme conservative; an opponent of progress or
         liberalism [syn: reactionary, ultraconservative,
         extreme right-winger]

Moby Thesaurus II by Grady Ward, 1.0:

170 Moby Thesaurus words for "reactionary":
   Bircher, Bourbon, Colonel Blimp, Epistle side, Methuselah, Tory,
   antagonistic, antediluvian, antipathetic, antiphonal, antique,
   atavistic, back number, bellyacher, bitter-ender, blimp, breakaway,
   clashing, clockwise, complainant, complainer, conflicting,
   conservatist, conservative, contradicting, contradictory,
   counteractant, counteracting, counteractive, countervailing,
   counterworking, crab, crank, cranky, croaker, crotchety, dad,
   decanal side, dexter, dextral, dextrocardial, dextrocerebral,
   dextrocular, dextrogyrate, dextrogyratory, dextropedal,
   dextrorotary, dextrorse, die-hard, diehard, dissident, dodo, elder,
   extreme right-winger, faultfinder, fogy, fogyish, fossil, frondeur,
   fud, fuddy-duddy, granny, griper, grouch, grouser, growler,
   grumbler, hard hat, has-been, hostile, imperialist, inimical,
   intransigent, kicker, kvetch, longhair, malcontent, matriarch,
   mid-Victorian, monarchist, mossback, murmurer, mutterer,
   nonconformist, nonprogressive, off, old believer, old crock,
   old dodo, old fogy, old liner, old man, old poop, old woman,
   old-line, old-timer, opposing, oppositional, oppugnant, orthodox,
   patriarch, perverse, pop, pops, querulous person, radical right,
   reacting, reactionarist, reactionist, reactive, rebel,
   recalcitrant, recessive, recidivist, recidivous, recto, reflex,
   reflexive, refluent, regressive, regular old fogy, relic, renitent,
   repugnant, resistant, respondent, responding, responsive,
   retroactionary, retroactive, retrocessive, retrograde,
   retrogressive, retrorse, retroverse, returnable, reversible,
   reversional, reversionary, revertible, revolutionary, revulsionary,
   revulsive, right, right field, right hand, right of center,
   right side, right wing, right-hand, right-wing, right-winger,
   right-wingish, rightist, royalist, social Darwinist, sorehead,
   square, standpat, standpatter, starboard, starboard tack, starets,
   tory, traditionalist, traditionalistic, ultraconservative,
   unprogressive, whiner, white