arcsecondWiktionary 原文构词拆分arc词根/词干+second词根/词干词源说明From arc + second.释义（英文）名词 NounA unit of angle; 1/60th of an arcminute, or 1/3600th of a degree.词族派生词（3）microarcsecondsubarcsecondmilliarcsecond相关词（1）arcminute