Primâ facie.—On the first view.

Primum mobile.—The primary motive, or moving power.

Primus inter pares.—Chief among equals.

Principia, non homines.—Principles, not men.

Principiis obsta.—Resist the first innovations.

Pro aris et focis.—For our altars and our hearths.

Pro bono publico.—For the public good.

Pro et con (for contra).—For and against.

Pro formâ.—For form’s sake; according to form.

Pro hâc vice.—For this turn or occasion.