The editors of the Oxford English Dictionary have reached out to readers around the globe, seeking an example of “def” used in popular culture before 1981. You can read the current “def” definition at this link.
Do you remember reading or listening to that word before 1981? You could get your find added to the prestigious dictionary. Here’s more from the editors, but you should read the whole fascinating post:
The word def, meaning ‘excellent; outstanding; “cool”’ is one of the earliest and most prominent terms to come to mainstream slang from hip-hop, but its early history is shrouded in confusion. The first clear example recorded in the OED is actually from language writer William Safire … it seems likely that def originated among rap musicians as a variant of death in expressions like to be death on in the sense ‘to be extremely good at’.