The Collaborative International Dictionary of English v.0.48:

Peucil \Peu"cil\ (p[=u]"s[i^]l), n. [Gr. pey`kh pine tree.]
   (Chem.)
   A liquid resembling camphene, obtained by treating turpentine
   hydrochloride with lime. [Written also peucyl.]
   [1913 Webster]