adjective. British slang. Not good; total crap; nonsense; rubbish; bad
"The first half of the movie was pants but I stayed until the end and it was actually a great film."
Sex that keeps you in bed for an extended period of time, only getting up to get food or go to the bathroom.
"Where you been the past few days, man?"
"I was on bed arrest with this amazing hottie I met at a club last weekend!"