2, II, two, deuce - the cardinal number that is the sum of one and one or a numeral representing this number

doubleton - (bridge) a pair of playing cards that are the only cards in their suit in the hand dealt to a player

Laurel and Hardy - United States slapstick comedy duo who made many films together

musical group, musical organisation, musical organization - an organization of musicians who perform together

pair - two people considered as a unit

same-sex marriage - two people of the same sex who live together as a family; "the legal status of same-sex marriages has been hotly debated"

primo - the principal part of a duet (especially a piano duet)

secondo - the second or lower part of a duet (especially a piano duet)

musical composition, opus, piece of music, composition, piece - a musical work that has been created; "the composition is written in four movements"