Definition of "trigonometry" [trig•o•nom•e•try]

• The branch of mathematics that deals with the relationships between the sides and the angles of triangles and the calculations based on them, particularly the trigonometric functions. (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.

• "The term trigonometry was not used until the close of the sixteenth century."
• "It makes me wonder if a kid who had no interest in trigonometry or symbolism in literature could grow up without ever learning those things and be okay."
• "Every edition released by the publisher has literally no new information (I can't imagine very many discoveries in trigonometry make their way into textbooks each year), but all new homework assignments."