intj

• (onomatopoeia) A sound mimicking the loss of air, as if someone's solar plexus had just been struck.
  "Whap, Biff, Ooooof, Sock, Pow, Zok! Batman is back. Gotham City is again leaving its law and order in the hands of a man who wears plastic underpants over his tights."
• (slang) Synonym of ouch (“expressing sympathy at another's pain, shock at a high price, etc.”).
  ""Oof, you just lost a lot of progress. That's a real frustration, a real punch in the gut.""

noun

• (Internet) Something cringeworthy, or which arouses disappointment, often used in conjunction with the qualifier big.
  "Fans were quick to express their disappointment at the removal of what has now become an iconic sound in the gaming space. The audio is trending on Twitter under #SaveTheOOF and Big Oof."

noun

• (UK, slang, dated) Money.
  "“Oh,” Johnnie was saying, “so Quest is his name, is it, and he lives in a city called Boisingham, does he? Is he an oof bird?” (rich) “Rather,” answered the Tiger, “if only one can make the dollars run, but he's a nasty mean boy, he is."