unlock

From Middle English unloken, unlouken, onlouken, from Old English unlūcan (“to unlock”), equivalent to un- +‎ lock. Cognate with Dutch ontluiken (“to unlock”).

• Rhymes: -ɒk

unlock (third-person singular simple present unlocks, present participle unlocking, simple past and past participle unlocked)

1. (transitive) To undo or open a lock or something locked by, for example, turning a key, or selecting a combination.

   I unlocked the door and walked in.

   The safe was already unlocked.

2. (transitive) To obtain access to something.
   • 2013 July 20, “Welcome to the plastisphere”, in The Economist, volume 408, number 8845:

     Plastics are energy-rich substances, which is why many of them burn so readily. Any organism that could unlock and use that energy would do well in the Anthropocene. Terrestrial bacteria and fungi which can manage this trick are already familiar to experts in the field.

   I unlocked the dictionary article so it could be edited.

   This computer game is shareware, but you can pay for a code to unlock the full version.

3. (transitive) To disclose or reveal previously unknown knowledge.

   The discovery of a clue unlocked the mystery.

4. (intransitive) To be or become unfastened or unrestrained.
   • 1912, Zane Grey, Riders of the Purple Sage, Chapter 8

     He had come straight up without mishap or swerving off his course, and his shut teeth unlocked.

unlock (plural unlocks)

1. The act of unlocking something.
   • 1998, Steven Herberts, The Correctional Officer Inside Prisons (page 38)

     Unlike modern, automated prisons, each cell here was locked and unlocked manually with a large skeleton key. The first duty was to get a proper head count of each inmate, insuring each was alive. Once done, an unlock was conducted.

   • 2011, Ganesh Gopalakrishnan, ‎Shaz Qadeer, Computer Aided Verification: 23rd International Conference

     The instructions between a lock and an unlock form a critical section.