The Collaborative International Dictionary of English v.0.48:

Propiolic \Pro`pi*ol"ic\, a. [Propionic + tetrolic.] (Chem.)
   Pertaining to, or designating, an organic acid (called also
   propargylic acid) of the acetylene or tetrolic series,
   analogous to propionic acid, and obtained as a white
   crystalline substance.
   [1913 Webster]