adj., n., & v.
adj. 1 of two; twofold. 2 divided in two; double (dual ownership). 3 Gram. (in some languages) denoting two persons or things (additional to singular and plural).
n. (also dual number) Gram. a dual form of a noun, verb, etc.
v.tr. (dualled, dualling) Brit. convert (a road) into a dual carriageway. dual carriageway Brit. a road with a dividing strip between the traffic in opposite directions. dual control (of a vehicle or an aircraft) having two sets of controls, one of which is used by the instructor. dual in-line package Computing see DIP. dual-purpose (of a vehicle) usable for passengers or goods. duality n. dualize v.tr. (also -ise). dually adv.
[ L dualis f. duo two ]