Initialism of other people's problems.

Initialism of Ontario Provincial Police, the police force of the Canadian province of Ontario.

Abbreviation of opposite.

(slang, among criminal gangs) An opponent; an enemy; the opposition / Abbreviation of opportunity.

Alternative spelling of opp (“opposite”)

Abbreviation of opuses.

A city in Alabama.

plural of opp

Misspelling of oops.

plural of OPP