Uhmderwhelmed 

(adj.) being so underwhelmed that you have no idea how to respond to such disappointment.

Hence the ”uhm.”

Synonym: Unimpressed

Boyfriend: So what do you think of that birthday gift I got you? You’re speechless I bet!
Girlfriend: Actually, the Alaskan timeshare has me uhmderwhelmed.

Uhmderwhelmed by DamnManilaMan October 3, 2019

underwhelmed 

unimpressed, unmoved, disappointed by lack of cerebral prowess or performance, failure to meet expectations, failure to provide evidence to support arguments

His performance did not wow me at all, I was totally underwhelmed.

underwhelmed by go big or go home January 1, 2004

underwhelmed 

Antonym of overwhelmed.

I was underwhelmed with the new vacation spot.

underwhelmed by geogoldman June 1, 2009