Its own dialect to a small group of college students in Iowa. The langauge of "meh" has only one syllable but can express any thought with proper inflection.
Singular use often indicates a relaxed, almost dazed state of mind.
-"Like, I know you can be overwhelmed, and I know you can be underwhelmed, but can you ever just be whelmed?"
"I think you can in Europe." -"10 Things"