The reciprocal of the tangent of an angle in a right triangle.(noun)
The tangent of the complement of a directed angle or arc.(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.
Use "cotangent" in a sentence
"It can also be used for such operations as involution (raising to a power) and evolution (extraction of a root) and for calculations with trigonometric functions (sine, cosine, tangent, cotangent)."
"Out on the various fronts the American soldiers grimly understood that they must hold on where they were for the sake of their comrades on other distant but nevertheless cotangent fronts on the circular line that guard Archangel."
"On this topic, it isn't completely clear to me why we make kids memorize what the secant, cosecant, and cotangent are."