an officer of middle rank in the army, navy, or air force, below captain
After years of training, Maria was promoted to lieutenant in the air force.
The lieutenant ordered her platoon to take cover behind the rocks.
✦ from Old French lieu ‘place’ + tenant ‘holding’, originally meaning ‘placeholder’ for a superior officer
someone who acts as the assistant or second-in-command to a leader or person in charge
In the company, Sara served as the CEO’s trusted lieutenant, organizing every major project.
The crime boss sent his most loyal lieutenant to negotiate the deal.
✦ figurative extension of the military sense, referring to anyone who ‘holds the place’ of a leader
