The Collaborative International Dictionary of English v.0.48:

Dipropargyl \Di`pro*par"gyl\, n. [Prefix di- + propargyl.]
   (Chem.)
   A pungent, mobile, volatile liquid, C6H6, produced
   artificially from certain allyl derivatives. Though isomeric
   with benzine, it is very different in its chemical relations.
   Called also dipropinyl.
   [1913 Webster]