dependency (n.)

1590s, "condition of being logically dependent; relation of a thing or person to that by which it is supported;" 1610s, "that which depends for its existence upon something else;" see dependent + -cy. Originally also dependancy, on the French model, but the Latinate form gradually pushed this into disuse; see -ance and compare dependant (n.). Meaning "territory subordinate to another nation" is recorded from 1680s.