melh₂-
“to grind, to crush”grind, mill, crush
Root for grinding, yielding Latin molere, English mill, meal, malt, mold.
Discussion
The PIE root *melh₂- (to grind, to crush, to pulverise) produced the vocabulary of milling and processing across the family — a word clan that connects the stone quern to the flour mill to the metaphorical grinding of daily labour.
Latin molere (to grind) and the derivative mola (millstone, mill) continue the root and generated: mill (the grinding machine and the building that houses it), molar (the grinding tooth), millet (a grain well suited to grinding), meal (ground grain — as in oatmeal, cornmeal), and the combining form -mill in windmill and watermill. The word emolument ("that which is ground out" — originally the miller's fee, then any payment for services) preserves the grinding metaphor in financial vocabulary.
Greek mýlē (μύλη, "mill, millstone") and the related mýlōn ("mill-house") continue the root in the Hellenic branch. The English word mylar (the trade name for a plastic film) is NOT from this root despite the phonetic similarity.
Old English melu (meal, ground grain, flour) preserves the native Germanic reflex. German Mehl (flour) and mahlen (to grind) confirm the cognate set. The English word maelstrom ("grinding-stream" — from Dutch maalstroom) names the whirlpool by the grinding motion of its waters.
Sanskrit mr̥ṇā́ti ("he crushes, he grinds") continues the Indo-Iranian reflex. Lithuanian málti (to grind) and Old Church Slavonic mlěti (to grind) confirm the Balto-Slavic forms.
The root's survival across every branch reflects the universality of grain-grinding in the PIE and post-PIE world. The quern (a hand-operated grinding stone) was one of the most essential tools of Neolithic and Bronze Age economies, and the PIE speakers who named the act of grinding generated a word that would endure through every revolution in milling technology — from the hand-quern to the water-mill to the industrial steel roller.
Notes
Pokorny 716-720. English mill, meal, molar, emolument.