Part of speech: adverb
(superl) 1. first, at first; previously, earlier; 2. first of all; 3. gram mean of an a first
Etymology
[Mod E ERST obs “at first; formerly” ← Prot-Germ *airistaz ← *airi → OE ǽr “earlier, formerly” + *-ista suff; O Sax ērist; Dt eerst; OHG ērist (Mod G erst)]
