Wiktionary
a. Not entertaining; dull.
WordNet
adj. not entertaining; "a quite unentertaining letter" [ant: entertaining]
Usage examples of "unentertaining".
He apologized for the rather unentertaining execution of Creeps Sharky, explaining the occasional need for such mercy.
I can only hope that as the trip was very entertaining to us, the record of it may not be wholly unentertaining to those of like tastes.
All including the chicken had to pause and investigate our curious encampment, making conversation with Holmes and eyeing his apparently dumb but not unentertaining companion.
Nor is the spectacle altogether unentertaining and uninstructive, which the history of those times presents to us.
He apologized for the rather unentertaining execution of Creeps Sharky, explaining the occasional need for such mercy.
Cal-Irvine had earned tenure with an essay arguing that the reason-versus-no-reason debate about what was unentertaining in Himself's work illuminated the central conundra of millennial après-garde film, most of which, in the teleputer age of home-only entertainment, involved the question why so much aesthetically ambitious film was so boring and why so much shitty reductive commercial entertainment was so much fun.