A person who is probably one of your closest friends but neither of you acknowledges that fact. They're somewhere between mortal enemy and best friend, hence the term "lukewarm".
Person One: Oh, is that your best friend? You hang out with them a lot.
Person Two: No, that's just my lukewarm enemy. It's a love-hate thing.
Person Two: No, that's just my lukewarm enemy. It's a love-hate thing.
by scramble21 June 22, 2020