The Collaborative International Dictionary of English v.0.48:

easygoing \eas"y*go`ing\, easy-going
\eas"y-go`ing\([=e]z"[y^]*g[=o]`[i^]ng), a.
   1. Moving easily; hence, mild-tempered; relaxed and casual;
      ease-loving; inactive. Contrasted with tense. [WordNet
      sense 2]

   Syn: degage, easy-going, laid-back.
        [1913 Webster + WordNet 1.5]

   2. having a lax moral or disciplinary standard. [WordNet
      sense 1] strict

   Syn: lenient.
        [WordNet 1.5]

   3. unhurried; as, an easygoing pace. Opposite of hurried.
      [WordNet sense 3]

   Syn: easy, leisurely.
        [WordNet 1.5]

   4. unaggressive; as, his easygoing approach to business.
      Opposite of aggressive. [WordNet sense 4]

   Syn: low-pressure.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

easygoing
    adj 1: not hurried or forced; "an easy walk around the block";
           "at a leisurely (or easygoing) pace" [syn: easy,
           easygoing, leisurely]
    2: not burdensome or demanding; borne or done easily and without
       hardship; "what a cushy job!"; "the easygoing life of a
       parttime consultant"; "a soft job" [syn: cushy, soft,
       easygoing]
    3: relaxed and informal in attitude or standards; "an easygoing
       teacher who allowed extra time for assignments"

Moby Thesaurus II by Grady Ward, 1.0:

187 Moby Thesaurus words for "easygoing":
   Bohemian, Micawberish, accepting, affable, afoot and lighthearted,
   airy, apathetic, at ease, at large, at liberty, ataractic,
   backward, blase, breezy, carefree, careless, casual, clear,
   clement, collected, comfortable, common, compassionate, composed,
   content, contented, cordial, cursory, dallying, degage, delaying,
   detached, devil-may-care, dilatory, dillydallying, disengaged,
   disinterested, dispassionate, disregardant, disregardful, drony,
   easy, emancipated, eupeptic, euphoric, even-tempered, faineant,
   familiar, flexible, flippant, folksy, foot-dragging, footloose,
   footloose and fancy-free, forbearant, forbearing, forgetful,
   forgiving, free, free and easy, free as air, freeborn, freed,
   gentle, go-as-you-please, gracious, happy, haymish, heedless,
   homely, homey, humane, impotent, imprecise, in the clear,
   inattentive, inconsiderate, incurious, indifferent, indolent,
   inexcitable, informal, insouciant, irregular, lackadaisical,
   laggard, lagging, lax, lazy, lenient, liberated, lingering,
   listless, loitering, loose, low-pressure, mellow, merciful, mild,
   mindless, moderate, natural, negligent, nonchalant, oblivious,
   of good comfort, offhand, offhanded, on the loose, overindulgent,
   overpermissive, patient, perfunctory, permissive, placid, plain,
   pleased, pococurante, poised, procrastinating, procrastinative,
   procrastinatory, reckless, reconciled, regardless, relaxed,
   released, remiss, resigned, respectless, sans souci, satisfied,
   scot-free, self-possessed, serene, shuffling, simple, slack,
   slipshod, sloppy, slothful, slow, sluggish, sociable, soft,
   tactless, tender, thoughtless, tolerant, tranquil, turned-off,
   unaffected, unambitious, unanxious, unassuming, unattached,
   unceremonious, uncommitted, uncomplaining, unconcerned,
   unconstrained, unconventional, undemanding, undiplomatic,
   undiscriminating, unengaged, unfussy, unheedful, unheeding,
   uninhibited, uninterested, uninvolved, unmindful, unofficial,
   unprepared, unready, unrepining, unreserved, unrestrained,
   unsolicitous, unstudied, untactful, unthinking, weak, wishy-washy,
   without care, work-shy