Webster's Revised Unabridged Dictionary · 1913

Est

Est , noun and adverb

East. [Obsolete] — Chaucer

-est (-est)

[Anglo-Saxon -ost, -est; akin to German -est, -ist, Icelandic -astr, -str, Gothic -ists, -ōsts, Sanskrit -ishtha.]

A suffix used to form the superlative of adjectives and adverbs; as, smoothest; earl(y)iest.