be somebody's middle name

be (one's) middle name

To be a trait that one readily displays or possesses a great amount of, or a thing that one considers to be closely associated with oneself. Often used humorously or ironically. Are we going to have fun? You bet, kid—"adventure" is my middle name! You don't need to worry about Donna—"safety" is her middle name.
See also: middle, name
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.

be somebody’s middle ˈname

(informal) used to say that somebody has a lot of a particular quality: ‘Patience’ is my middle name!
See also: middle, name
Farlex Partner Idioms Dictionary © Farlex 2017
See also: