blue-on-blue 

Denoting or relating to an attack made by one's own side that accidentally harms one's own forces.

The only thing more accurate than incoming enemy fire, is incoming friendly fire.

blue-on-blue by caxwl July 8, 2004

Blue on Blue 

Referring to when a police officer testifies against another police officer in a court of law.

Its a rare thing when you have a Blue on Blue in a court trial. You can't help but think: "somebody fucked up"!

Blue on Blue by talk2me-JCH2 April 2, 2021

Blue on Blue 

Jargon used by police (blue) to indicate they are firing a weapon and that other officers should take care to avoid getting caught in the crossfire. In the 911 call transcript of the Tiger attack at the San Francisco zoo, an officer was heard announcing a "Blue on blue".

Officer is firing, blue on blue!

Blue on Blue by Gorn Dog January 17, 2008

Blue-on-Blue Brutality 

When an off-duty, retired, separated, plainclothes, or undercover law enforcement officer gets beaten up by uniformed on-duty law enforcement officers in marked units because they are often mistaken for criminals due to LEOSA privileges.

To prevent Blue-on-Blue brutality many agencies across the nation often require officers to provide visible identification to uniformed on duty officers in marked units during traffic stops or stop and frisk operations to avoid field interrogation cards by uniformed personnel.

Blue-on-Blue Brutality by kinghiroichi1 September 25, 2025

Left me on blue 

When you are an iPhone user and you text someone and they never texted back

Damn, I was wanting to hang out but dude left me on blue

Left me on blue by Shapeshifter/guardians 1111 April 29, 2020

Put Clouds on Blue Sheets 

The act of cumming on a blue bed sheet, blanket, etc.

Guy: Shit, I just put clouds on blue sheets, my moms gonna fuck me in the ass now

Put Clouds on Blue Sheets by Fluff_Sucker_69 June 9, 2018

death on blue legs 

A clan that originates in the game called Planetside. The greatest clan on planetside, with many members and high morals. Also we have hilarity, which no other outfit can offer.

"but you teamkilled me!!"
"dont mess with death on blue legs, bitch!"

death on blue legs by Azreal677 / GeneralKevinLiakan / ShdwCypher / RoXst3R April 26, 2004