This is the 7221st most frequent Spanish word.
galaxia
A galaxy.
Here, 'galaxia' refers to a large system of stars, like the Milky Way.
La galaxia en la que vivimos se llama la Vía Láctea.
The galaxy we live in is called the Milky Way.
In this sentence, 'galaxia' signifies a type or category of these celestial systems.
Cada galaxia contiene miles de millones de estrellas.
Each galaxy contains billions of stars.
Here, 'galaxias' is used in plural to describe multiple occurrences of such celestial entities.