Webster's Revised Unabridged Dictionary · 1913

Greaten

Greaten , transitive verb

To make great; to aggrandize; to cause to increase in size; to expand. [Rare]
A minister's [business] is to greaten and exalt [his king]. — Ken

Greaten , intransitive verb

To become large; to dilate. [Rare]
My blue eyes greatening in the looking-glass. — Mrs. Browning