Of or pertaining to the Old Prussian language or people.

An extinct Baltic language, once spoken by the Old Prussians, the indigenous peoples of the historical region of Prussia (now north-eastern Poland, the Kaliningrad Oblast of Russia and Lithuania).

A member of the Baltic tribe that historically inhabited Prussia; a Baltic Prussian.

plural of old penny

A former student of Eton College

(informal) One's elderly relations. / (informal) The old people of a particular place or social situation. / (informal) Senior citizens.

(US, idiomatic, informal, chiefly Southern US) Emphatically or impressively big; really big.

Reactionary or conservative. / Long-established.

(informal) The Devil.

A (comparatively) conservative, reactionary faction that is more unwilling to accept new ideas than their peers are. / Collectively, the members of a team who have been a long time in a place.