be up (one's) alley(redirected from be up their alley)
be up (one's) alley
To be suited to or aligned with one's interests. I really like Romantic poetry, so this class on John Keats should be up my alley. I'm sure Dave can fix your car—mechanical things like that are up his alley.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.