The Collaborative International Dictionary of English v.0.48:

Salicylal \Sal"i*cyl`al\, n. [Salicylic + aldehide.] (Chem.)
   A thin, fragrant, colorless oil, HO.C6H4.CHO, found in the
   flowers of meadow sweet (Spiraea), and also obtained by
   oxidation of salicin, saligenin, etc. It reddens on exposure.
   Called also salicylol, salicylic aldehyde, and formerly
   salicylous acid or spiroylous acid.
   [1913 Webster]