too clever by half

annoyingly proud of one's intelligence or skill and in danger of overreaching oneself.

"he always was too clever by half"

half time watch

When a movie is so bad you can't even bear a one time watch.
"OR"
When you leave mid-movie/interval.

"Bro,you went to watch the latest tw***ght flick right? How was it?"
"Hey! Hey! Not so loud Brah! -_- And It wasn't even a half time watch"

Half vegan

When you eat half a salad and a half hamburger

So do you like meat Ashley?
I'm half vegan so I only eat half a steak and half a salad .
Okay that's great ! Let's go to a steakhouse!

Half-Vegan

Someone who is vegan but only eats meat when it is 50% off

"Im no fully vegan, im Half-Vegan. It still counts though"

half-first great-cousin-aunt

Grandparent’s female half-first cousin.

My half-first great-cousin-aunt is a good person.

half-first cousin-nephew

Half-first cousin's son.

My half-first cousin-nephew is a good boy.

half Spock

Fingering your girlfriend in both holes, using the index and middle finger. A full Spock would be using your index and middle fingers in one hole, and the ring and little finger in the other.

My lady wasn't satisfied with only a half Spock, so I had to add more fingers.