Top definition
The unique currency men from the west of Ireland use to pay for somebody's mothers services.
Dublin Man: Yo P-Dawg, what you get up to last night?

P-Dawg: I spend me last manky fiver on a go of your Ma.

Dublin Man: Ugh..
by PDawgWillRideYourMaInTheBog April 10, 2014
Get the mug
Get a Manky Fiver mug for your papa James.