Meaning

noun United States architect who was the presidentially appointed architect of Washington D.C. (1781-1855)

noun a plant consisting of one or more buildings with facilities for manufacturing

noun Scottish philosopher who expounded Bentham's utilitarianism; father of John Stuart Mill (1773-1836)

originFrom mills, in reference to mill owners and mill workers.

Etymology from Wiktionary, CC BY-SA 3.0