Ason; offspring; progeny. The tender imp was weaned.N . A lad of life, an imp of fame.

A subaltern or puny devil.

To graft.

To lengthen; to extend or enlarge by something inserted or added; a term originally used by falconers, who repair a hawk’s wing by adding feathers. Imp out our drooping country’s broken wings. --The false north displays IVP. Her broken league to imp her serpent wings. This verb is, I believe, used only in poetry.