Sine (noun)

1. A trigonometric function, defined as the ratio of the side opposite an angle in a right triangle to the hypotenuse.
2. A mathematical function that describes a wave-like oscillation or periodic phenomenon.

Origin:

From latin sinus ("a bend, fold, curve, bay") and from the greek word συν (syn) meaning together and the greek word εἶδος (eidos) meaning form or shape, coined by the ancient greek mathematician and physicist pythagoras, around the 5th century bc.

Examples:

1. The sine of the angle is equal to the opposite side divided by the hypotenuse.
2. The sine function is used in trigonometry.
3. The sine curve is used to describe simple harmonic motion.
4. The sine wave is used to describe alternating current.
5. Sine and cosine are two of the most important functions in trigonometry.