Do that make it word..?

Nah, Hev! As specified in the dictionary, that makes these terms interjections. I think you could argue that interjections shouldn't really be in the dictionary in the first place. Like, how do you spell them?

Is uh the same as huh or uhh ?

Is er the same as erm or ehm ?

Do um, er and uh mean more or less the same thing anyway?

If you don't have a consistent set of spellings and meanings, you ain't got much of a word, eh? (or hein? as belM may have it..)

I find myself writing a fair amount of hmmmms, a supposedly thoughtful interjection. But the written words lie - in reality I say errrmmmms a lot more.
Eek, the truth is out now.

Fisk