Metaphorically speaking, for one's stomach to either get a boner or become moist.
"Damn I'm starving. What are you making for dinner over there?"
"We ordered a buffalo chicken pizza and 3 orders of fries"
"Aww shit girl, you getting me so horngry right now."
Mark: Come on, baby, lots of people use food in their foreplay. I thought you would find it romantic.
Arlene: Yeah, okay. I understand the whip cream and strawberries, but what's up with the bacon and the tuna melt on rye?
Mark: I can't help it, I'm so horngry.
The giant statue of Ronald McDonald made Ryan confusingly but incredibly horngry.