also mould, "hollow shape," c. 1200, originally "fashion, form; nature, native constitution, character," metathesized from Old French modle "model, plan, copy; way, manner" (12c., Modern French moule), from Latin modulum (nominative modulus) "measure, model," diminutive of modus "manner" (from PIE root *med- "take appropriate measures"). From c. 1300 as "pattern or model by which something is shaped or made." To break the mold "render impossible the creation of another" is from 1560s.
also mould, "furry fungus," early 15c., probably from moulde, past participle of moulen "to grow moldy" (early 13c.), related to Old Norse mygla "grow moldy," possibly from Proto-Germanic *(s)muk- indicating "wetness, slipperiness," from PIE *meug- (see mucus). Or it might have evolved from (or been influenced by) Old English molde "loose earth" (see mold (n.3)).
also mould, "loose earth," Old English molde "earth, sand, dust, soil; land, country, world," from Proto-Germanic *mulda (source also of Old Frisian molde "earth, soil," Old Norse mold "earth," Middle Dutch moude, Dutch moude, Old High German molta "dust, earth," Gothic mulda "dust"), from PIE root *mele- "to crush, grind." Specifically, since late (Christian) Old English, "the earth of the grave."
also mould, mid-14c., "to mix, blend;" late 14c. "to knead, shape," from mold (n.1). Figurative sense (of character, etc.) is from c. 1600. Related: Molded; molding.