Source : Webster's Revised Unabridged Dictionary (1913)

Megilp \Me*gilp"\, Megilph \Me*gilph"\, n. (Paint.)
   A gelatinous compound of linseed oil and mastic varnish, used
   by artists as a vehicle for colors. [Written also {magilp},
   and {magilph}.]

Source : WordNet®

megilp
     n : a medium for oil-paints; linseed oil mixed with mastic
         varnish or turpentine [syn: {megalp}]