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).(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.