ASTROMETER
As*trom"e*ter, n. Etym: [Astro- + meter.]

Defn: An instrument for comparing the relative amount of the light of stars.

ASTROMETRY
As*trom"e*try, n. Etym: [Astro- + metry.]

Defn: The art of making measurements among the stars, or of determining their relative magnitudes.

ASTRONOMER
As*tron"o*mer, n. Etym: [See Astronomy.]

1. An astrologer. [Obs.] Shak.

2. One who is versed in astronomy; one who has a knowledge of the laws of the heavenly orbs, or the principles by which their motions are regulated, with their various phenomena. An undevout astronomer is mad. Young.

ASTRONOMIAN
As`tro*no"mi*an, n. Etym: [OE. & OF. astronomien. See Astronomy.]

Defn: An astrologer. [Obs.]

ASTRONOMIC
As`tro*nom"ic, a.