What is a galaxy?

Noun

• S: (n) galaxy (a splendid assemblage (especially of famous people))
• S: (n) galax, galaxy, wandflower, beetleweed, coltsfoot, Galax urceolata (tufted evergreen perennial herb having spikes of tiny white flowers and glossy green round to heart-shaped leaves that become coppery to maroon or purplish in fall)
• S: (n) galaxy, extragalactic nebula ((astronomy) a collection of star systems; any of the billions of systems each having many stars and nebulae and dust) "`extragalactic nebula' is a former name for `galaxy'"

Source: http://wordnetweb.princeton.edu/perl/webwn?s=galaxy