Verb
(transitive, informal) To point one's firearm at another person, thereby gaining dominance in a situation.
He got the drop on them and proceeded to shoot and kill them before they could fire a shot or respond.
(transitive, informal, by extension) To obtain an advantage over another person, by acting before that person.
Synonyms: beat to the punch, get the jump on
We’re always getting the drop on our competitors because the owner really knows the business and can act fast.
All he has to do is get the drop on the marshal and the Kid. Source: Internet
Twenty years ago as a beat cop no one would have been able to get the drop on her. Source: Internet