The Collaborative International Dictionary of English v.0.48:

Leisure \Lei"sure\ (l[=e]"zh[-u]r; 135), n. [OE. leisere,
   leiser, OF. leisir, F. loisir, orig., permission, fr. L.
   licere to be permitted. See License.]
   1. Freedom from occupation or business; vacant time; time
      free from employment.
      [1913 Webster]

            The desire of leisure is much more natural than of
            business and care.                    --Sir W.
                                                  Temple.
      [1913 Webster]

   2. Time at one's command, free from engagement; convenient
      opportunity; hence, convenience; ease.
      [1913 Webster]

            He sighed, and had no leisure more to say. --Dryden.
      [1913 Webster]

   At leisure.
      (a) Free from occupation; not busy.
      (b) In a leisurely manner; at a convenient time.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Leisure \Lei"sure\, a.
   Unemployed; as, leisure hours.
   [1913 Webster]

WordNet (r) 3.0 (2006):

leisure
    n 1: time available for ease and relaxation; "his job left him
         little leisure" [syn: leisure, leisure time]
    2: freedom to choose a pastime or enjoyable activity; "he lacked
       the leisure for golf"

Moby Thesaurus II by Grady Ward, 1.0:

47 Moby Thesaurus words for "leisure":
   at leisure, at liberty, at loose ends, available, disengaged, ease,
   fallow, free, free time, freedom, holiday, idle, inactive, jobless,
   leisured, liberty, lumpen, off, off duty, off work, open,
   opportunity, otiose, out of employ, out of harness, out of work,
   quiet, recreation, recreational, relaxation, relief, repose,
   respite, rest, resting, retired, semiretired, spare, spare time,
   time off, tranquillity, unemployable, unemployed, unencumbered,
   unhurriedly, unoccupied, vacation