underwhelm
From Longman Dictionary of Contemporary Englishunderwhelmun‧der‧whelm /ˌʌndəˈwelm $ -ər-/ verb [transitive] IMPRESS#if you are underwhelmed by something, you do not think it is impressive – used humorously OPP overwhelm We were underwhelmed by the latest version of the software.→ See Verb tableOrigin underwhelm (1900-2000) under + -whelm (as in overwhelm)