late 14c., "to soften (a substance)," from Old French mollifier or directly from Late Latin mollificare "make soft, mollify" from mollificus "softening," from Latin mollis "soft" (from PIE root *mel- (1) "soft") + combining form of facere "to make, to do" (from PIE root *dhe- "to set, put"). Transferred sense of "soften in temper, appease, pacify" is recorded from early 15c. Related: Mollified; mollifying.
