Home › Words › A › arcsecondarcsecondarcsecond means A unit of angle; 1/60th of an arcminute, or 1/3600th of a degree.EtymologyFrom arc + second.nounA unit of angle; 1/60th of an arcminute, or 1/3600th of a degree.Definitions & examples from Wiktionary (CC BY-SA 3.0).Words closest in meaningBy meaning, not spelling — each word's AI semantic fingerprint, nearest first.arcminute 79% match — A unit of angle; 1/60 of a degree. vs arcsecond →milliarcsecond 70% match — A unit of angle equal to one thousandth of an arcsecond (used especially in astronomy) vs arcsecond →arcdegree 70% match — A unit of measurement of angle equal to ¹⁄₃₆₀ of a circle's circumference. vs arcsecond →semiarc 58% match — half of an arc vs arcsecond →attosecond 57% match — An SI unit of time equal to 10⁻¹⁸ seconds. Symbol: as vs arcsecond →microradian 57% match — A unit of angle equal to one millionth of a radian. vs arcsecond →arcsecant 56% match — function that is the compositional inverse of the secant function. Symbol: arcsec vs arcsecond →attoparsec 56% match — A unit of measure of 10⁻¹⁸ parsecs, or about 3.085 centimetres (1.215 inches). vs arcsecond →