What is Tappet?
1.
Moving part of an engine that rattles when loose resulting in engine failure. Slang usage as someone who's tappets are slightly loose (not quite with it - a.k.a someone who is a few sandwiches short of a picnic)
South African variation is of a tappet being a
Donny is a real tappet.
Harvey is so tappet
See
Random Words:
1.
A word used to describe something awesome, cool or nice/good looking.
"That chick was the real damn deal"
"That car is ..