A·cher·nar 
(
āk
ər-när
′)
n. A star in the constellation Eridanus that is one of the brightest stars in the sky and is 114 light years from Earth.
[From Arabic 'aḫīr an-nahr, the end of the river (referring to the star's position in the constellation Eridanus) : 'aḫīr, last, end; see ʾḫr in the Appendix of Semitic roots + al-, the + nahr, river; see nhr in the Appendix of Semitic roots.]