Source : Webster's Revised Unabridged Dictionary (1913)

Tiglic \Tig"lic\, a. (Chem.)
   Of, pertaining to, or designating, an acid, {C4H7CO2H}
   (called also methyl crotonic acid), homologous with crotonic
   acid, and obtained from croton oil (from {Croton Tiglium}) as
   a white crystalline substance.