Earlier and Erstwhile

Earlier adjective - (comparative and superlative of `early') more early than; most early.

Erstwhile is a synonym for earlier in precede topic. In some cases you can use "Erstwhile" instead the word "Earlier" as an adjective or an adverb, when it comes to topics like before, formerly.

Erstwhile adjective - Having been such at some previous time.

Earlier is a synonym for erstwhile in time topic. You can use "Earlier" instead the word "Erstwhile" as an adjective or an adverb, if it concerns topics such as precede, before, formerly.