IPA: /ˌkɒn.stəˈleɪ.ʃən/
KK: /kɒnˈstɛləˌʃən/
A group of stars that form a pattern in the night sky, often named after mythological figures or objects. It can also refer to a gathering of notable people or things.
The night sky was filled with a beautiful constellation of stars.
Constellation → It is formed from "con-" (meaning together) and "stella" (meaning star). The word refers to a group of stars that are perceived to form a pattern or shape in the night sky, hence stars that are together in a recognizable formation.
Think of stars being 'together' ('con-') to form a pattern or shape, which is what a constellation is.