Having two beats per measure, in music

• Consisting of two
• Involving two parts
• Twofold
• Of two
• Having two beats to the measure
• Double line crossed by Patsy

Wiktionary Word definitions in Wiktionary
a. 1 (context rare English) double. 2 (context of time or music English) Having two beats, or a multiple of two beats, in each measure. 3 (context poetry English) Having two beats in each foot.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Duple \Du"ple\, a. [L. duplus. See Double .] Double. Duple ratio (Math.), that in which the antecedent term is double the consequent, as of 2 to 1, 8 to 4, etc. [1913 Webster] ||

WordNet Word definitions in WordNet
adj. consisting of or involving two parts or components usually in pairs; "an egg with a double yolk"; "a double (binary) star"; "double doors"; "dual controls for pilot and copilot"; "duple (or double) time consists of two (or a multiple of two) beats ...