The biomechanical term that defines a single, complete cycle of motion is called

The right answer is period (periodic motion).

A phenomenon is periodic when it reproduces, identical to itself, at the end of a certain time called period.

A periodic phenomenon is a phenomenon that is reproduced, identical to itself, at equal time intervals. An example of periodic movement in biology in the heart rhythm: even if a physical activity can modify their rhythm, the heart beats represent a good example of periodic phenomenon.

70 % i think is the answer.