cosine cosinage • cosiness · · · Info · Definitions · Synonyms · Characters · · cosine · · Text Latin · · Script 6 · · Length Definitions · · · (noun) ratio of the adjacent side to the hypotenuse of a right-angled triangle. Synonyms: cos. · · Noun Definition 1 Synonyms · · · cos · · Synonym 1 Characters · · c latin small letter c U+0063 e latin small letter e U+0065 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F s latin small letter s U+0073