sine
noun /saɪn/
/saɪn/
(abbreviation sin)
(mathematics)- the ratio of the length of the side opposite one of the angles in a right-angled triangle that are less than 90° to the length of the longest side compare cosine, tangentTopics Maths and measurementc2Word Originlate 16th cent.: from Latin sinus ‘curve’, used in medieval Latin as a translation of Arabic jayb ‘pocket, sine’.