(verb) The act of becoming so unhealthily involved with one's significant other as to completely withdraw from the world The person crawls up inside of their boyfriend or girlfriend's life much like the titular vermin, using only their large right claw as a doorway/camoflage preventing others from identifying he/she. The person only emerges every once in a while to nab a piece of
food (rejoin society briefly), and then scurries back into his/her hidey hole. The culprit will continue to do
this until the signficant other is no longer hospitable or he/she outgrows them, then he/she will have to move on to another person, or find a tin can or
other such shelter.
"That guy has been hermitcrabbing for like three months now. Is he even alive?"