get (one's) number(redirected from get one's number)
get (one's) number
1. To obtain someone's phone number, often when there is a romantic interest between the two people. Oh please, there's no way you'll be able to get that hot girl's number.
2. To understand or know someone or something well enough to anticipate what they will do. Oh, don't worry, I've got his number—he's a typical brat.
get someone's number
Also, have someone's number. Determine or know one's real character or motives, as in You can't fool Jane; she's got your number. This expression uses number in the sense of "a precise appraisal." Charles Dickens had it in Bleak House (1853): "Whenever a person proclaims to you, 'In worldly matters I'm a child,' ... that person is only crying off from being held accountable ... and you have got that person's number." [Mid-1800s]