Definition of "lockup"

(slang) A jail cell, or a period of incarceration.

(UK, chiefly) A storage unit with a door secured by a padlock or deadbolt; a garage.  examples

(mechanical engineering) A condition in which one or more of a vehicle's wheels suddenly cease to rotate due to the application of excessive brake torque, causing the affected wheel(s) to skid.  examples

(computing) A condition where a system stops responding to inputs; a freeze.  examples

(printing, historical) A device for locking type into position for printing.

(marketing, by extension) A fixed layout involving one or more logos and possibly related text.  examples