# Sine meaning

sīn
The ordinate of the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point (1, 0) if x is positive or clockwise if x is negative.
noun
In a right triangle, the ratio of the length of the side opposite an acute angle to the length of the hypotenuse.
noun
The reciprocal of the cosecant.
• The ratio of the opposite side of a given acute angle in a right triangle to the hypotenuse.
• An equivalent, positive or negative ratio for certain related angles (Ex.: the sine of 57° or 123° is .8387, of 237° or 303° is −.8387) or real numbers representing radians (Ex.: the sine of .9948 radians (57°) is .8387).
noun
Without.
preposition
The ratio of the length of the side opposite an acute angle in a right triangle to the length of the hypotenuse.
The ordinate of the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point (1, 0) if x is positive or clockwise if x is negative.
In a right triangle, the ratio of the side opposite an acute angle (less than 90 degrees) and the hypotenuse. The cosine is the ratio between the adjacent side and the hypotenuse. These angular functions are used to compute circular movements.
(trigonometry, mathematics) In a right triangle, the ratio of the length of the side opposite an angle to the length of the hypotenuse.
noun
A function of a number x , equal to the sine of an angle whose measure in radians is equal to x.

## Origin of sine

• Medieval Latin sinus (mistranslation of Arabic jayb sine) (as if jayb fold in a garment) from Latin curve, fold

### From American Heritage Dictionary of the English Language, 5th Edition

• From Latin sinus, originally by mistranslation of Arabic Ø¬Ø¨ (jubb). Ultimately from Sanskrit.