Emily Dickinson Lexicon

LIEU-TEN'ANT, n. [luten'ant; Fr.; composed of lieu, place, and tenant, L. tenens, holding.]

1. An officer who supplies the place of a superior in his absence. Officers of this kind are civil, as the lord-lieutenant of a kingdom or county; or military, as a lieutenant-general, a lieutenant-colonel.
2. In military affairs, the second commissioned officer in a company of infantry, cavalry or artillery.
3. In ships of war, the officer next in rank to the captain.