unison

/ˈjunəsən/
noun
  1. The act of doing something together at the same time; simultaneous action or speech.
    • The dancers moved in unison, creating a beautiful pattern on stage.
    • The choir sang in perfect unison, their voices blending as one.
    • The students answered the question in unison, surprising the teacher.
  2. Complete agreement or harmony of opinion, feeling, or purpose.
    • The two countries acted in unison to address the climate crisis.
    • The family worked in unison to clean up after the party.
    • The committee acted in unison to approve the new policy.
  3. In music, the sounding of the same note by two or more voices or instruments at the same pitch or an octave apart.
    • The violin and flute played the melody in unison.
    • The chorus began the song in unison before splitting into harmonies.
    • The orchestra ended the piece with all instruments in unison.