the basic unit of force in the FPS system, equal to the force which imparts an acceleration of one foot per second per second to a mass of one pound (0.1383 newton or 13,825.5 dynes): abbrev. pdl
See poundal in American Heritage Dictionary 4
(pounˈdl)
noun
A unit of force in the foot-pound-second system of measurement, equal to the force required to accelerate a standard one-pound mass one foot per second per second (approximately 0.138 newton).