n. [ F.; cf. It. pastello. Cf. Pastil. ] 1. A crayon made of a paste composed of a color ground with gum water. [ Sometimes incorrectly written pastil. ] “Charming heads in pastel.” W. Black. [ 1913 Webster ]
2. (Bot.) A plant affording a blue dye; the woad (Isatis tinctoria); also, the dye itself. [ 1913 Webster ]