adj., n., & adv.
adj. 1 (predic.) owing or payable as a debt or an obligation (our thanks are due to him; $500 was due on the 15th). 2 (often foll. by to) merited; appropriate; fitting (his due reward; received the applause due to a hero). 3 rightful; proper; adequate (after due consideration). 4 (predic.; foll. by to) to be ascribed to (a cause, an agent, etc.) (the discovery was due to Newton). 5 (predic.) intended to arrive at a certain time (a train is due at 7.30). 6 (foll. by to + infin.) under an obligation or agreement to do something (due to speak tonight).
n. 1 a person's right; what is owed to a person (a fair hearing is my due). 2 (in pl.) a what one owes (pays his dues). b a legally demandable toll or fee (harbour dues; university dues).
adv. (of a point of the compass) exactly, directly (went due east; a due north wind). due to disp. because of, owing to (was late due to an accident) (cf. sense 4 of adj.). fall (or become) due (of a bill etc.) be immediately payable. in due course 1 at about the appropriate time. 2 in the natural order.
[ ME f. OF de ult. f. L debitus past part. of debere owe ]