The Collaborative International Dictionary of English v.0.48:

Janissary \Jan"is*sa*ry\, n.
   See Janizary.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Janizary \Jan"i*za*ry\, n.; pl. Janizaries. [F. janissaire,
   fr. Turk. ye[~n]i-tsheri new soldiers or troops.]
   A soldier of a privileged military class, which formed the
   nucleus of the Turkish infantry, but was suppressed in 1826.
   [written also janissary.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

janissary
    n 1: a loyal supporter; "every politician has a following of
         janissaries"
    2: a Turkish soldier