The phrase "a less ebullient" is correct and usable in written English.
It can be used when describing something or someone that is not as enthusiastic or lively as another.
Example: "After the disappointing news, the team was a less ebullient version of its former self."
Alternatives: "a more subdued" or "a quieter".
All of this is so heavy and acrid with irony that, were a less ebullient writer in charge, it could have sunk the whole book.
The discovery of his affliction with the incurable disease of mediocrity might have cowed a less ebullient spirit, but he remained bright-eyed, with a ready smile for the world.
It was a less ebullient Hugo Chávez than usual who addressed his compatriots from Havana, where he was recovering from a second major operation to remove a cancerous growth.
As they did well in the bull market, so should value stocks provide superior returns in a less ebullient environment.
Meanwhile, back at the Gap, where the deinstallation of the collection has been proceeding for over a month, the mood is a bit less ebullient.
Art fairs and dealers are suddenly a lot less ebullient.
His companion on the front row seemed a little less ebullient than usual at David Cameron's right-hand side at Prime Minister's Questions at lunchtime.
General Franks was less ebullient a few days later.
His small congregation, of mostly West Indians of Indian ancestry, worships in a style only slightly less ebullient than that of its Jamaican neighbors.
But Thomas Woodhamanaging a managing director of Mallett Inc., a specialist in English and Continental furniture with showrooms in London and New York, was less ebullient about a bounce-back.
This is in part why David Warner's occasionally successful attempts to master opening in England – head down one day, bat blazing the next – are so absorbing, the spectacle of a pure batting athlete trying to master a skill that less talented, less ebullient, more obviously scarred and cautious players have mastered before him.
