The Collaborative International Dictionary of English v.0.48:

Breakaway \Break"a*way`\, n. [Break + away] [Australasia]
   1. A wild rush of sheep, cattle, horses, or camels
      (especially at the smell or the sight of water); a
      stampede.
      [Webster 1913 Suppl.]

   2. An animal that breaks away from a herd.
      [Webster 1913 Suppl.]

   3. an object designed to break off or shatter under impact,
      as a safety measure.
      [PJC]

   4. (Sport) the sudden emergence of one or more players or
      contestants from a clustered group, rushing toward a goal,
      as bicyclists in a race, or baketball players after a
      rebound has been caught.
      [PJC]

WordNet (r) 3.0 (2006):

breakaway
    adj 1: having separated or advocating separation from another
           entity or policy or attitude; "a breakaway faction" [syn:
           breakaway, fissiparous, separatist]
    n 1: the act of breaking away or withdrawing from; "there was a
         breakaway by the discontented members"; "a breaking away
         from family and neighborhood" [syn: breakaway, breaking
         away]

Moby Thesaurus II by Grady Ward, 1.0:

124 Moby Thesaurus words for "breakaway":
   Bohemian, abjuratory, alienated, antagonistic, antiestablishment,
   antipathetic, apostasy, at odds with, at variance with,
   backsliding, beat, betrayal, bolt, clashing, conflicting,
   contradicting, contradictory, counter-culture, counteractant,
   counteracting, counteractive, countervailing, counterworking,
   cranky, crotchety, defection, dereliction, deserter, desertion,
   differing, disagreeing, disloyalty, dissentient, dissenting,
   dissident, extreme, extremistic, factious, faithlessness, far out,
   free and easy, fringy, going over, heretical, heterodox, hippie,
   hostile, in opposition, informal, inimical, insurgent,
   insurrectionary, kinky, maverick, mugwumpian, mugwumpish,
   mutineering, mutinous, nonconforming, nonconformist, not cricket,
   not done, not kosher, offbeat, opposing, oppositional, oppugnant,
   original, perverse, rare, ratting, reactionary, rebel, rebellious,
   recalcitrant, recherche, recidivation, recidivism, recreancy,
   recusant, renitent, renunciative, renunciatory, repudiative,
   repudiatory, repugnant, resistant, revocatory, revolutional,
   revolutionary, riotous, schism, schismatic, secession,
   secessionist, sectarian, sectary, seditionary, seditious,
   separatist, subversive, sui generis, traitorous, treason,
   treasonable, turbulent, turning traitor, uncommon, unconventional,
   uncustomary, underground, undreamed-of, unexpected, unfamiliar,
   unfashionable, unheard-of, unique, unordinary, unorthodox,
   unthought-of, unusual, unwonted, walkout, way out