Half crack
A medical anomaly when someone's crack only extends halfway up his or her butt.
Omg, Emily! Turn around and look in the mirror. You've got a half crack!
half cracked
condition where a person is not yet drunk, but still under the influence of alcohol.
Friend was half cracked while at the beach, glazing at the sun
Half back crack
An extremely unnaturally long ass crack
Look at her half back crack.