1. [verb] To plan together; to settle or adjust by conference, agreement, or consultation.
2. [verb] To plan; to devise; to arrange.
3. [verb] To act in harmony or conjunction; to form combined plans.
4. [noun] (uncountable) Agreement in a design or plan; union formed by mutual communication of opinions and views; accordance in a scheme; harmony; simultaneous action.
5. [noun] (uncountable) Musical accordance or harmony; concord.
6. [noun] (countable) A musical entertainment in which several voices or instruments take part.
7. [noun] A performance of music by players or singers not involving theatrical staging.
8. [verb] Contrive (a plan) by mutual agreement.
9. [verb] Settle by agreement; 'concert one's differences'.