megilp

/məˈɡɪlp/
noun
  1. A jelly-like substance made from linseed oil and mastic varnish, used as a medium in oil painting.
    • Megilp was a popular painting medium in the 19th century.
    • The artist mixed megilp with her oil paints to create a glossy finish.
    • He learned that using too much megilp can cause the paint to crack over time.