sine
|sine|
/saɪn/
curved ratio; without
Etymology
'sine' (the Latin preposition used in English phrases) originates from Latin, specifically the word 'sine', where 'sine' meant 'without'.
'sine' (the mathematical term) changed from Latin 'sinus' (meaning 'bay, fold, curve'), via Medieval Latin and Old French forms (from translations and transmissions of astronomical and mathematical texts, which themselves reflect Arabic translations), and eventually became the modern English mathematical word 'sine'. The mathematical adoption also reflects an earlier chain from Sanskrit 'jya-' (half-chord) through Arabic 'jayb' to Medieval Latin 'sinus'.
For the prepositional sense, it originally meant 'without' in Latin and retains that meaning in fixed phrases in English. For the mathematical sense, the original idea was 'bay/curve' (Latin 'sinus') and over time this developed into the technical meaning of the trigonometric function 'sine'.
Meanings by Part of Speech
Noun 1
in trigonometry, the function (or ratio) of an angle equal to the length of the side opposite the angle divided by the length of the hypotenuse; also used to refer to a sine wave.
The sine of 30° is 0.5.
Synonyms
Noun 2
(Borrowed from Latin) the Latin preposition meaning 'without', found in fixed Latin phrases used in English (e.g., 'sine qua non').
In legal writing, 'sine' appears in the phrase 'sine qua non'.
Synonyms
Idioms
Last updated: 2026/01/14 16:13