Noun - Someone that has drank so much that they have gotten to the stage of throwing up. The term is really used for a person that is, has or is about to vomit.
Verb - Whether if they throw up in a bucket, the toilet, or on themselves, they are still crankin that bucketman.
" I was so drunk last night that i had to crank dat bucketman."
"Josh is about to throw up, you better bucketman that hoe."
" You better give him a bucket so he can bucketman that hoe, before he throws up on your couch."