The Collaborative International Dictionary of English v.0.48:

Irenic \I*ren"ic\, Irenical \I*ren"ic*al\, a. [Gr. ?.]
   Fitted or designed to promote peace; pacific; conciliatory;
   peaceful. --Bp. Hall.
   [1913 Webster]

WordNet (r) 3.0 (2006):

irenic
    adj 1: conducive to peace; "irenic without being namby-pamby";
           "an irenic attitude toward former antagonists"

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "irenic":
   appeasing, civilian, conciliatory, dovish, mollifying,
   nonaggressive, noncombatant, nonmilitant, nonviolent, pacific,
   pacificatory, pacifist, pacifistic, pacifying, peace-loving,
   peaceable, peaceful, placative, placatory, propitiative,
   propitiatory, reconciliatory, soothing, unbellicose, uncontentious,
   unhostile, unmilitant, unmilitary