Definition of "parallelogram" [par•al•lel•o•gram]

• A four-sided plane figure with opposite sides parallel. (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.

• "*This is reputed to be the first rock song to contain the word parallelogram in it."
• "A square only requires a peg at each corner, with a chalked string drawn from peg to peg; and an oblong, or parallelogram, is made by joining two common squares, and taking off the corners if required."
• "This addition rule is known as the parallelogram law."