The phrase "a cusp of" is correct and usable in written English.
It can be used to describe a point of transition or a critical moment between two different states or conditions.
Example: "We are on the cusp of a new era in technology, where artificial intelligence will play a central role in our daily lives."
Alternatives: "on the brink of" or "at the threshold of".
The more I saw, the more I felt on a cusp of a brave new world – like witnessing the switch from radio to TV.
"I don't think that behavioral targeting is something that we should eliminate, but I do think that we're at a cusp of a new era, and the kinds of information that companies share and have today is nothing like we'll see 10 years from now," Professor Turow said.
"I think he sees that we are at a cusp of philosophical changes in the Legislature and across the state over what we've been doing the past few years with accountability and whether there's been any worthwhile gain from all the testing we've done," said Joe Smith, a former superintendent and an education community fixture who runs the Web site TexasISD.com, a clearinghouse of school-related news.
Pakistan appears to be on a cusp of enormous if not bloody changes.
This implies that the origin of (3.3), that is, of (1.6), is a cusp of codimension by in [25, Theorem, Section ].
The equilibrium of (1.6) is a cusp of codimension if (H1) and (H2) hold; that is, it is a Bogdanov-Takens singularity.
Like Hollis, singer and lyricist Guy Garvey has a cusp-of-quiet-desperation catch in his voice as he floats across Little Beast, a portrait of smalltown, small-time ennui and violence, and wearily lists his own failings in death- rattle fashion on the even more etiolated Can't Stop.
Time slows down everywhere at this hour on a cusp-of-fall weekend, but here in Clinton, Ontario, a somnolent slip of a town (population 3,500) that is easy to miss after a three-hour drive from Toronto during which you pass nothing but mile after flat mile of fields punctuated by grazing cows and horses, the stillness is so vast that it seems almost cautionary.
He said, "We are on a great cusp of history.
But it also offers a metaphor for a world on the cusp of a social earthquake.
That's a shame for a country on the cusp of a full blown economic meltdown.
