Find the word definition

Douglas Harper's Etymology Dictionary
contra dance

1803, from French contre-danse, altered from English country dance by folk etymology from French contra "against," suggested by the arrangement of the partners in the dance. The dances and the name were taken up in France c. 1720s and from there passed to Spain and Italy (Spanish, Italian contra danza) then back to English.

Wiktionary
contra dance

n. (context dance English) A type of folk dance style in which couples dance in two facing lines of indefinite length.

Wikipedia
Contra dance

Contra dance (also contradance, contra-dance and other variant spellings) is a folk dance made up of long lines of couples. It has mixed origins from English country dance, Scottish, French dance styles in the 17th century, with strong African influence from Appalachia. Sometimes described as New England folk dance or Appalachian folk dance, contra dances can be found around the world and have much popularity in North America and the United Kingdom where weekly or monthly dances and annual dance weekends are common. According to the Contra Dance Links website, contra dancing can be found in all US states except for South Dakota.

Considered a social dance that one can attend without a partner, but is danced in pairs, contra dancing is danced in long lines of couples/pairs formed starting from the stage and down the dance hall. Throughout the course of a dance, couples progress up and down these lines, dancing with each other couple in the line. The dance is led by a caller who teaches the sequence of figures in the dance before the music starts. Callers describe the series of steps called "figures", and in a single dance, a caller may include anywhere from 6–12 figures which are repeated as couples progress up and down the lines. Each time through the dance takes 64 beats, after which the pattern is repeated.

The music played for contra dances includes, but is not limited to Irish, Scottish, old-time and French-Canadian folk tunes. The fiddle is considered the core instrument, though other stringed instruments such as the guitar, banjo, bass and mandolin are played as well. Music in a dance can consist of a single tune or a medley of tunes, and key changes during the course of a dance are common.