To bring things into harmony, or to make things compatible.
To provide parts to.
To provide the harmony for a melody.
To be in harmonious agreement.
To play or sing in harmony.
To get involved or involve oneself, causing disturbance.
To sexually molest, especially of a child.
(of waves) To be correlated with each other when overlapped or superposed.
To strike one foot against the opposite foot or ankle in using the legs.