Source : Webster's Revised Unabridged Dictionary (1913)

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.

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

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

            He sighed, and had no leisure more to say. --Dryden.

   {At leisure}.
      (a) Free from occupation; not busy.
      (b) In a leisurely manner; at a convenient time.

Source : WordNet®

at leisure
     adj : idle; between jobs; (euphemism for `unemployed') [syn: {at
           leisure(p)}]
     adv : in an unhurried way or at one's convenience; "read the
           manual at your leisure"; "he traveled leisurely" [syn:
           {leisurely}]