to fail to make a good impression or have a significant impact on
Origin of underwhelmironic allusion to overwhelm
transitive verbun·der·whelmed, un·der·whelm·ing, un·der·whelms
To fail to excite, stimulate, or impress: “He is just as entitled to be underwhelmed by the prospect of reigning over a fourth-class nation as the rest of us are by the prospect of living in it” (Peter Jay).
Origin of underwhelmunder– + (over)whelm.
(third-person singular simple present underwhelms, present participle underwhelming, simple past and past participle underwhelmed)