adj. Failing to interest; usually used in response to something that was presented as exciting.
the GNU version of the Collaborative International Dictionary of English
adj. Less interesting than expected; dull.
adj. Smaller than expected or hoped.
Word Usage
"Bossier City and Shreveport turned out in underwhelming numbers last night - maybe 30 or 40 people in front of Buffalo Wild Wings at the Louisiana Boardwalk, and those were probably shoppers passing by."