The Collaborative International Dictionary of English v.0.48:

Sirup \Sir"up\Syrup \Syr"up\, n. [F. sirop (cf. It. siroppo, Sp.
   jarabe, jarope, LL. siruppus, syrupus), fr. Ar. shar[=a]b a
   drink, wine, coffee, sirup. Cf. Sherbet.]
   1. A thick and viscid liquid made from the juice of fruits,
      herbs, etc., boiled with sugar.
      [1913 Webster]

   2. A thick and viscid saccharine solution of superior quality
      (as sugarhouse sirup or molasses, maple sirup);
      specifically, in pharmacy and often in cookery, a
      saturated solution of sugar and water (simple sirup), or
      such a solution flavored or medicated.
      [1913 Webster]

            Lucent sirups tinct with cinnamon.    --Keats.
      [1913 Webster]

   Mixing sirup. See the Note under Dextrose.
      [1913 Webster] Siruped

WordNet (r) 3.0 (2006):

sirup
    n 1: a thick sweet sticky liquid [syn: syrup, sirup]