Measurement of angular separation: a 1-inch stick would subtend an angle of 1 arcsec at a viewer's eye at a distance of about 6.5 miles.

a 60th part of a minute of arc; "the treasure is 2 minutes and 45 seconds south of here"

a fraction of an arcminute

a unit of angular measurement

The second division of a degree of arc. One sixtieth of an arcminute. (1/3600th of a degree.)

One-sixtieth of a minute of arc. 1/3600 of a degree.

(") A measure for very small angles. 1 arcsecond = 1/60 arcminute = 1/3600 degree.

a unit of angular size equal to 1/3,600 of a degree (or 1/60 of an arcminute).

A small measure of angular distance. There are 60 arcseconds in one arcminute and therefore 3600 arcseconds in one degree.