tock

This word is almost exclusively used as part of the onomatopoeic pair "tick-tock." While it can function independently, it rarely appears without the implied or explicit presence of "tick," as the two sounds together create the rhythmic representation of a mechanical clock's movement.

As a noun, it represents the lower-pitched or second beat of the cycle. As a verb, it describes the act of producing this specific sound, though it is far less common than the verb "tick."