Floor is wet 

The -“floor is wet” is a line from prison meaning the patrol officers are doing the runs, this can also be used on teachers

Person on Lookout: THE FLOOR IS WET
Everyone scatters back to doing what they’re doing and the teacher greets everyone with awards for doing great work

Floor is wet by an unkown gender hello December 10, 2017

floor is wet 

A prison term for when a hair enters the cell block. It means to hide everything your doing

(Guard enters) Sam: Floor is wet!
Gavin: Oh no I have to hide my gun!

floor is wet by NathanOG March 14, 2017

the floor is wet 

A slang in prisons across US that is implying on nearby guards that are coming to search and/or check on prisoners. It's used between inmates to warn each other of upcoming possible guard.
Is also refereed to as "the floor is soaking wet" or "the floor is really wet" which means that C.O.'s know something is up, and the inmates should really hurry up with covering up any possible "unacceptable or illegal actions".

*THE FLOOR IS WET* screamed an inmate as he warned his inmates from possible danger.

the floor is wet by Frankliiin January 14, 2017