lock-in 

a group gathering where you are "locked" in a building. It may include games, movies, but never sleeping! sleeping is for losers :oP

Lauren and Monica went to the lock-in and didn't sleep. They were up till 6am

lock-in by Monica Jo July 3, 2007

Lock-in 

Lock in - (noun)

The term used for when the pub doors get locked after hours for the locals. This is a more common occurance rural towns over England when the locals are allowed to drink and smoke after hours inside the pub freely with the landlords permission.

You know you’re part of a lock in when the blinds or curtains are pulled, the ashtrays come out from behind the bar and drinks are still being poured. This normally continues under the landlord discression as after closing time it is simply his property.

If you ever get the chance to attend one don’t turn it down, but never question what goes on.

Any of you boys fancy going to the pub tonight? I heard it’s going to be another lock-in.

Lock-in by Raver666666666 June 16, 2018

Lock-In 

A special gathering or sleepover that takes place in a building from dawn 'till dusk, or 12 hours. At the beginning you're doing a bunch of activities and games, watching the movies the chaperones provide, until usually 9 hours in. And at this time everyone becomes either testy, zombie like, hyper, or bored. Usually the activities cease (except for the video game tournaments and the movies) and everyone falls asleep or just talks about a boring subject. By this time the food is all gone, so everyone is scavenging for any scrap of sugar.

The lock-in started at 7 pm and ended at 7 am. I think I passed out at 4 am.

Lock-In by TestyWhenHungry May 14, 2011

lock-in 

popular slang for a homodyne with an extremely low pass filter, which making it very narrow band. Usually includes a frequency mixer, and not to be confused with bandpass filter.

"That lock-in is essentially shot-noise limited."

"I'm using the reference from that lock-in because I don't have a function generator."

lock-in by novakyu December 25, 2007

Lock-In 

Drinking within a Pub after opening hours, the landlord allows a group to keep drinking after all other customers have left. They have locked all the doors, hence it being called a Lock In. When a Lock-In is permitted it usually results in a legendary sesh.

John the pub landlord allowed us to do a lock-in and keep seshing into the morning.

Lock-In by Ellis_ April 6, 2023

Lock in 

To ready and prepare yourself

“I’m going to lock in for the frat house birthday!”

Lock in by tp219 June 7, 2021

lock in 

The largely illegal state of a bar or pub during the period of time after last call, during which the bar is locked to all incoming would-be patrons such tha bar employees and a select group of friends can sit around and drink without all the annoying cash-paying customers bugging them.

this guy kinda blew her off, so she was all like "i need to croosh someone NOW," drags me down the sidewalk and five minutes later we're in a lock in with 5 guys

lock in by Landau December 7, 2006