Source : Webster's Revised Unabridged Dictionary (1913)

Hireling \Hire"ling\ (-l[i^]ng), n. [AS. h[=y]reling. See
   {Hire}, n., and {-ling}.]
   One who is hired, or who serves for wages; esp., one whose
   motive and interest in serving another are wholly gainful; a
   mercenary. ``Lewd hirelings.'' --Milton.

Hireling \Hire"ling\, a.
   Serving for hire or wages; venal; mercenary. ``Hireling
   mourners.'' --Dryden.

Source : WordNet®

hireling
     n : a person who works only for money [syn: {pensionary}]