Duff
Matelots used to use it to describe their 'afters'. 'Plum duff', figgy duff'. which is old world.
You can, of course, 'come your duff'. or, indeed, be 'up the duff'.
But we can all sleep safely in our beds, from a health and safety point of view, if we always wear our 'ear duffs' to protect our hearing.
Go figure.