I. ˈd(y)]üəl, ]u̇əl also ]ül\ adjective
Etymology: Latin dualis, from duo two + -alis -al — more at two
1. of an inflectional form or grammatical number : denoting reference to two
Gothic wit “we two” is a first person dual pronoun
— compare plural , quadrual , singular , trial
2.
a. : consisting of two parts or elements : double , twofold
the dual tones of an American toad's song — W.P.Smith
that the work of a painter who looks important in England … has stood up to the dual test of international competition and the Adriatic sun — David Sylvester
b. : having two aspects : having a double character or nature
the man had a dual nature, one half positive and passionate to yearning, one half negative, satirical, and really perverse — H.S.Canby
immigrants, as a rule, retain a dual patriotism — Bertrand Russell
c. : containing two or being one of two often identical parts : twin
high-compression heads complete with a dual exhaust system — Gregor Felsen
d. : consisting of or used on a pair of wheels (as automotive driving wheels) joined together side by side (as by bolting or welding) on a common axle
dual tires
3. : characterized by a division of controlling agents or factors: as
a. : consisting of two sets of authorities having mutually exclusive spheres of power
a dual federalism
a dual form of government
b. : fitted for operation by either or both of two agents
driving lessons given on dual -control cars
dual -fuel engines that run on oil or oil and gas
II. noun
( -s )
1. : the dual number of a language or a form in it
2. : the result obtained in consequence of interchanging conjunction and alternation throughout a formula in the propositional calculus
3. : a chess problem for which two solutions exist
4. : a pair of dual wheels or dual tires