fuck-in 

noun: a large gathering of people that fornicate in a public setting as a sign of protest.

When Abbie Hoffman, a popular activist of the late sixties, decided to form a mass protest at the 1968 Democratic Convention in Chicago, one of his ideas to protest American involvement in the Vietnam War was to get thousands of yippie and SDS protesters to fornicate on the public grounds of Grant Park (which was one of the larger and popular parks along the lakeside)- thus, a fuck-in.

fuck-in by chaoticmeadows October 12, 2006

Fuck in

Where as a demonstration against something men and women occupy a room in a building and have an orgy that is public sex that only stops when there demands are met. They often chain themselves to something to make it hard for the police ect. to drag them off.

Did you hear about that fuck in they had at our school to day?

Fuck in by Deep blue 2012 December 22, 2009

Fuck'in 

A term used as a conjunction for fuck and ing.

ex. "Give me your fuck'in money!" - Law and Order Special Victims Unit

Fuck'in by BiBipepe6969 January 10, 2020

Fuck In

To boot or smash in/up, can also be used to describe what you are going to do to someone.

Aye, fuck in his windaes, he's a dobber!
or
Ah'm gonnae fuck in your face ya fanny!

Fuck In by I am not a ned! February 10, 2005

fuck in law

Someone whom has had sexual relations with a person whom you have also had sex with.

O me and lisa go way back we both were shagged by giles so we are fuck in laws too.

fuck in law by Sirus May 15, 2003

fuck in a bucket 

Similar to phrases like oh my god or jesus christ, fuck-in-a-bucket is meant to be exlamatory or an adjective to describe someone particularly insane or eccentric.

"Oh fuck in a bucket, Suzy got caught drunk driving."

"She's such a fuck in a bucket."

fuck in a bucket by queen.padme.amidala June 18, 2006

Fuck-in-Law 

The relationship you have with anyone that has already had sex with the person you’re currently sleeping with.

Bob banged Susan at that party last year, guess that makes us fuck-in-laws.

Fuck-in-Law by Sigar Cel November 25, 2003