old people's pot, generally known for it's better quality

OPP ONLY stands for Other Peoples Pussy
NOT Penis/Privates/Ect.
See OPP by Naughty By Nature

if you listen to the lyrics of the song opp

Other peoples pussy id the main definition
then there's one for the ladies - other peoples penis

property is for G-rated rhyming radio play purposes

1. other people's property.
2. other people's privates.
3. other people's penises.
4. other people's pussies.

Other People's Pussy or Other People's Penis.

Stands For Other Peoples Pussy/Other Peoples Penis
It is asking the listener if he/she is willing to have sexual relations with a person who is known to already have a boyfriend or girlfriend.

Many popular definitions of OPP include:
Other People's Property
Other People's Privates
Other People's Penis
Other People's Pussy

but in a VH1 presentation of the 100 Greatest Hip Hop Songs, Treach of Naughty by Nature states
"OPP can stand for anything, the first O is Other and the second P is People's but the last P can stand for anything."

Ontario Provincial Police.