Maybe my fear is irrational and/or premature, but given Graceful_Lolita's answer, I tend to think that technology is going to make language change too quickly. Granted, language change is inevitable, but at the rate texting/electronic technology seems to be changing it, I would be curious if I can thoroughly understand a text message/e-mail in 10 years. I write all this because I thought "oomf" was a word or sound that comic writers/cartoons put in a speech bubble if there character got struck in the stomach or something. One thing is for sure. Technology is definitely decreasing attention spans. (Maybe that is why ADD--Attention Deficit Disorder seems to be on the rise.)
No wonder! I believe you're looking at two similar words, with similar, rather energetic meanings, mistaken for one another and stuck together--kind of like Brangelina, but not as good-looking. I think one word is "oof," the comic-strip/Stooges response to getting socked in the gut; the other, "oomph," is from the 1930s, and means exciting, energetic, or sexually attractive.