A party a man's friends throw for him before he gets married. There is often heavy drinking and/or strippers (i.e. all the things that he won't be able to enjoy once he's married.)
Two weeks after Tom and Becky's engagement, Tom's friends blindfolded him, threw him in the back of their car, and took him to Layla's Tongue Shop in downtown Harlem. Then next morning, still hungover, he thanked them for a great bachelor party.
An attempt by a man's friends to celebrate their bachelorhood by filling a weekend with as many vivid illustrations and experiences to make said man hyper-aware of all of the great things about bachelorhood that he will be giving up.
I can't wait to go to my bachelor party so all of my friends can have an awesome time doing all of things I can no longer do.