IPA: /ljuˈtɛnənsi/
KK: /ljuˈtɛnənsi/
The position or rank of a lieutenant in a military or police organization.
He was promoted to the lieutenancy after years of dedicated service.
Lieutenancy is derived from "lieutenant" (from Old French *lieutenant*, meaning 'deputy' or 'one who holds a place') and the suffix "-cy" (meaning the state or condition of). The term refers to the state or condition of being a deputy or holding a position of authority in the absence of a superior.
Think of a 'lieutenant' as someone who acts in place of another, and the '-cy' indicates a state or condition, so 'lieutenancy' means the state of being a deputy.