Definitions for "Offbeat"
Keywords:  beat, upbeat, weak, halfway, rhythmic
emphasis on the weak beats in a measure
The second "half" of a beat (which might actually be shorter than half a beat in a swing rhythm)
An imaginary beat placed halfway between two beats. If you were tapping your feet, the upbeat would occur when your toe reached its highest point off the ground.
informal terms; strikingly unconventional