From Longman Dictionary of Contemporary Englisha lock on somethinga lock on somethingAmerican English complete control of something Pro football still has a lock on male viewers aged 18 to 34. → lock
Examples from the Corpus
a lock on something• His parents were not surprised when he asked for a lock on his bedroom door before he had reached his teenage years.• Republicans in Congress, used to having a lock on the White House, began attacking Clinton at once.• The lack of a lock on the one and only toilet was compensated for by the frosted glass panels in the door.• For security a lock on the front locks both the system and the keyboard.• Straightening, she reflected soberly that the only thing missing was a lock on the bedroom door. 