Zestlessly is a derived term of zestless.
As an adverb zestlessly
is in a zestless way.
As an adjective zestless is
lacking zest; passionless, unenthusiastic.
Other Comparisons: What's the difference?
In a zestless way.
* 1945 , , The Perfect Round
- "Shrimps That Crawl in Chesapeake Bay, Served Up Fresh Here Every Day," he rhymed zestlessly from old habit.
Lacking zest; passionless, unenthusiastic.