The Collaborative International Dictionary of English v.0.48:

Harmaline \Har"ma*line\ (h[aum]r"m[.a]*l[i^]n or -l[=e]n), n.
   [Cf. F. harmaline See Harmel.] (Chem.)
   An alkaloid found in the plant Peganum harmala. It forms
   bitter, yellow salts.
   [1913 Webster]