What does "sexagesimal" mean?

Sexagesimal: Pertaining to, or founded on, the number sixty. Sexagesimal fractions or numbers (Arith. & Alg.), those fractions whose denominators are some power of sixty; as, astronomical fractions, because formerly there were no others used in astronomical calculations. -- Sexagesimal, or Sexagenary, arithmetic, the method of computing by the sexagenary scale, or by sixties. -- Sexagesimal scale (Math.), the sexagenary scale.