An illness caused by sudden onset of feels, specifically the Ls. Symptoms include butterflies, daydreaming, lightheadedness, and growing attachment to the individual responsible for this illness. More often than not, it sneaks up on the individual. Symptoms increase when both individuals share the same illness.
I feel funny.
Dude, I think you're head over heels from this chick!
A moribund metaphor meaning "out of controlin love." But, think about it. Aren't you head over heels every day? Shouldn't it be "heels over head in love"?
"Ah, she was nothing special. I'm only head over heels for Angelina. But I'm heels over head in love with Sandra."
"I'm absolutely head over heels for you."
"You're delusional."
"Call it what you will, I think its the best feeling in the world."
"Yeah I'm pretty sure I know the feeling."
"<3"