Noah Webster
Imp
IMP, noun
1. A son; offspring; progeny.
The tender imp was weaned.
A lad of life, an imp of fame.
2. A subaltern or puny devil.
IMP, verb transitive
1. To graft.
2. 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
Her broken league to imp her serpent wings.
This verb is, I believe, used only in poetry.