transitive verb. To fail to excite, stimulate, or impress.

transitive verb. To interest less than anticipated; to be dull to (a person).

verb. To fail to impress; to perform disappointingly.

"It's a version of what might be called the "underwhelm" phenomenon – when journalists archly declare themselves to be "underwhelmed", as if informing the reader: do you see what I did?"

overwhelm  

Helm  elm  helm  overwhelm  realm  

underwhelmed  underwhelming  underwhelms