contra

noun6

1. •
   (disapproving) A conservative; originally tied to Nicaraguan counter-revolutionaries.
2. •
   A contra dance.
3. •
   (US, New-England) A country dance.

   • Folk histories record that contras were gradually displaced by the introduction of the quadrille and the new couple dances. — 2001
4. •
   [before a noun] An entry (or account) that cancels another entry (or account).

   • The sum for each contra account is shown in the last column.
5. •
   A deal to swap goods or services.
6. •
   (informal) Any of the musical instruments in the contrabass range, e.g. contrabassoon, contrabass clarinet or, especially, double bass.

adverb1

1. •
   Contrary to something.

   • […] it is useless to pray “Thy kingdom come” and vote contra or stay away from the polls; […] — 1893

preposition1

1. •
   Against; contrary or opposed to; in opposition or contrast to.

verb1

1. •
   To undo; to reverse.

noun1

1. •
   A member of any of various rightist guerrilla groups violently opposing the socialist Sandinista government of Nicaragua and secretly funded by the United States government in the 1980s.