Trough

Real World Example

Imagine waiting for your bus during rush hour, and there’s a lull when no buses are arriving. Just like this lull represents the absence of activity, the trough in a transverse wave is the lowest point where the wave dips the furthest from its resting position. In both cases, the lull and the trough signify a point of minimal presence—whether it's the scarce buses or the low energy of the wave—before things pick up again with either the next bus or the crest of the wave.