Sexagesimal is a mathematical term that refers to a system of counting or measuring in base 60. Some synonyms for sexagesimal include the terms sexagenary, which is used to describe something related to 60 or a set of 60 things, and sexadic, which refers to a numbering system that is based on 60. Other related terms include base 60, which is a counting system in which each place value is a power of 60, and sextant, which is an instrument used in navigation that is divided into 60 equal parts. In general, these synonyms all relate to the use of the number 60 in mathematical or navigational contexts.