[1] : The Collaborative International Dictionary of English v.0.48

inaction \inac"tion\, n. pref. in. not + action: cf.
   inaction.
   lack of action or activity; forbearance from labor; idleness;
   rest; inertness. --berkeley.
   1913 webster

[2] : WordNet (r) 2.0

inaction
     n 1: the state of being inactive syn: inactivity, inactiveness
          ant: action, action, action
     2: a state of no activity syn: inactiveness
see also:
inactivity inactiveness action 

[3] : Moby Thesaurus II by Grady Ward, 1.0

21 moby thesaurus words for "inaction":
   dormancy, drift, fixation, fixity, hibernation, idleness,
   immobility, inactiveness, inactivity, indolence, inertia,
   inertness, lethargy, lull, motionlessness, quiescence, slackness,
   slothfulness, suspension, torpidity, underactivity

Inaction >> I Words
Inaction, definition of term: Inaction
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