First Known Use: 1593
Dictionary
sine
noun \ˈsīn\
geometry : the ratio between the long side (called the hypotenuse) and side that is opposite to an acute angle in a right triangle
Full Definition of SINE
1
: the trigonometric function that for an acute angle is the ratio between the leg opposite the angle when it is considered part of a right triangle and the hypotenuse
2
: a trigonometric function sin θ that for all real numbers θ is exactly equal to the sine of an angle of measure θ in radians and that is given by the sum of the alternating series
See sine defined for English-language learners
See sine defined for kids
ADVERTISEMENT
Origin of SINE
Medieval Latin sinus, from Latin, curve
Learn More About SINE
Browse
ADVERTISEMENT
Seen & Heard
What made you want to look up sine? Please tell us where you read or heard it (including the quote, if possible).