Other forms: unlocked, unlocking, unlocks
Unlock is what you do to a lock so a thing will open. You unlock the front door with a key, unlock your phone with your thumb, unlock a bike from the rack outside the shop.
The word has travelled a long way from keys. Software unlocks a feature when you pay, a game unlocks the next level when you finish this one, and a good teacher unlocks a child's confidence. Anything shut away and then made available gets unlocked. Unlocked works as an adjective too — an unlocked door, an unlocked phone — and the opposite is simply lock. One thing learners get wrong: unlocking a door does not open it. You turn the key, then you push.
1verbunlockTo open a lock, or open something held shut by a lock, with a key or a code.
“He unlocked the gate and held it open with his foot.”
synonyms: unbolt, unfasten
2verbreleaseTo make available something that was closed off — a feature, a level in a game, an ability in a person.
“Finishing the last level unlocks a new track.”
synonyms: release, open up
Old English already had onlūcan, meaning to unlock — un- stuck on the front of lock, the same trick English still uses today. Middle English carried it on as unloken and unlouken. Dutch kept a cousin of it in ontluiken.
Old English
onlūcan — to unlock
Middle English
unloken
English, today
unlock
From Middle English unloken, unlouken, onlouken, from Old English onlūcan (“to unlock”), equivalent to un + lock. Cognate with Dutch ontluiken (“to unlock”).
Etymology from Wiktionary, CC BY-SA