Literal meaning (edge or point):
* The ancient city stood on the cusp of a steep cliff, overlooking the valley below.
* The knife was so sharp that it cut the paper cleanly, leaving a perfect cusp at the edge.
Figurative meaning (transitional point):
* The company is on the cusp of a major breakthrough in its research.
* She stood at the cusp of adulthood, unsure of what the future held.
* The world was on the cusp of a new era of technological advancement.
* The country is on the cusp of a political revolution.
Other uses:
* The cusp of a tooth can become worn down over time.
* The cusp of the wave crashed against the shore.
The meaning of "cusp" in each sentence depends on the context. It can refer to a literal edge or point, or it can be used figuratively to represent a transitional or pivotal moment.