un·der·whelm 
(ŭn′dər-wĕlm, -hwĕlm)
(ŭn′dər-wĕlm, -hwĕlm)tr.v. un·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).
[UNDER- + (OVER)WHELM.]