The Spanish word "estrella" (meaning "star") comes from the Latin word "stella", which also meant "star". When this word was adopted into Spanish, a prothetic 'e-' was added at the beginning. This addition of 'e-' before words beginning with 's + consonant' was a common phonological development in Spanish, as native Spanish speakers found it difficult to pronounce initial 's + consonant' clusters. This same pattern can be seen in other Spanish words like "escuela" (from Latin "schola") and "espacio" (from Latin "spatium").

Some related Spanish words include "estelar" (stellar), "constelación" (constellation), and the verb "estrellarse" (to crash, literally "to become a star"). The connection between "estrellarse" and "estrella" comes from the visual effect of seeing "stars" when hitting one's head, which evolved into a general term for crashing or collision.

English speakers can easily remember "estrella" by connecting it to English words like "stellar" (relating to stars), "constellation" (a group of stars), and "interstellar" (between stars). All these words come from the same Latin root "stella". The main difference is that Spanish added the 'e-' at the beginning, while English preserved forms closer to the original Latin.