supplement: n. & v. --n. 1 a thing or part added to remedy deficiencies (dietary supplement). 2 a part added to a book etc. to provide further information. 3 a separate section, esp. a colour magazine, added to a newspaper or periodical. 4 Geom. the amount by which an angle is less than 180Û (cf. COMPLEMENT). --v.tr. provide a supplement for. øøsupplemental adj. supplementally adv. supplementation n. [ME f. L supplementum (as SUB-, plere fill)]