The Collaborative International Dictionary of English v.0.48:

acrylic \a*cryl"ic\ ([.a]*kr[i^]l"[i^]k), a.
   1. (Chem.) Of or containing acryl, the hypothetical radical
      (R.CH:CH.CO-) of which acrolein (H2C:CH.CHO) is the
      hydride; as, acrylic acid. The characteristic residue in
      an acrylic compound is the carbonyl group attached
      directly to an ethylenic carbon.
      [1913 Webster +PJC]

   2. Of or pertaining to a derivative of acrylic acid, or an
      object consisting mostly of an acrylic resin; as, an
      acrylic window.
      [PJC]