panoramic camera

phonograph

pie in the face gag

Pictionary

Puzz-3D

process to extract bromine

Phi (position homing indicator) (for aircraft)

plexiglass

paint roller...invented by Norman Breakey of Toronto in 1940

personal distress device

portable high chair

A Question of Scruples

radio quiz shows

rollerskate

RADAR

RADAR profile recorder

railway car brake...invented by George B. Dorey in 1913 

railway sleeper car...invented by Samuel Sharp in 1857

radio compass

Robertson screw