You searched for: “galaxies
galaxy (s), galaxies (pl)
1. A congregation, or large grouping, of millions or billions of stars, held together by gravity or gravitational attraction and also known as an "island universe".
2. A collection of dust, gas, and stars measuring thousands of parsecs across.

A parsec comes from PARallax + SECond which is a unit of distance between stars. One parsec is about 3 1/4 light years.

This entry is located in the following unit: Astronomy and related astronomical terms (page 11)
(the science of the celestial bodies: the sun, the moon, and the planets; the stars and galaxies; and all of the other objects in the universe)