In the UK, typically somewhere like teeside, this is a phrase to say as a way to promise XYZ is the truth. Mainly used in secondary schools.
Dean: stop chatting shit about my dead nana ya specky cunt!
Mackenzie: what are you on about!?
I didn't say nish. What are you piping up for?
Dean: swear down then.
Mackenzie: mam's life I didn't say ought (out) about your nana, kid fuckin' hell man.
Mackenzie: what are you on about!?
I didn't say nish. What are you piping up for?
Dean: swear down then.
Mackenzie: mam's life I didn't say ought (out) about your nana, kid fuckin' hell man.
by 49seffy March 14, 2022
Get the mam's lifemug. by Hansipeter August 11, 2020
Get the Dei mammug. by amasteas July 5, 2019
Get the ya mammug. 
by cracklingballspop91 August 5, 2022
Get the joe mammug. by Skinny 💅🏼 July 10, 2019
Get the Lil mammug. Young girl from Hartlepool who acts like/looks like a man, usually with a layered bob, who isn't a mam
by marcowh August 21, 2023
Get the Mam headmug.