Just Playing with Words

Circumnavigate,
Circumcise,
Concise,
Conquest,
Request,
Relieve,
Believe,
Beneath,
Underneath,
Underpants.

For some reason I had the "Understand, Underpants" bit in my head. I saw the pattern and wondered how I would go about using it. It's surprisingly difficult, particularly when the first word that came into my head to start the series was "Circumnavigate". I considered trying to go for the whole alphabet, but remembered that life is finite.