A Boo Radley is the point of focus of a voyeuristic observation.
"Hey John. Check out that Boo radley over there. You can see right up her skirt."
Any expectionally unattractive female. Boo Radley's typically hail from places like Boo City, Iowa. Wall Streeters refer to Boo Radley's as triple boo minus, if EXCEPTIONALLY UGLY, single boo minus. Variants include "rad" or "boo"
"Man, that girl is totally boo-radley." "I'm a seller of that boo radley, she's like single boo minus."
Creepy person that has a certain charm to them. Also a stalker. From the book To Kill a Mockingbird.
OMG, that Boo Radley is coming after me!
when something is so rad that it scares the shit of you.
"...so it turns out that the spooky dude who lives down the street isn't retarded, he's just a recluse and he saved a little girl's life the other night."
"are you serious?"
"yeah man. and he used to be in a gang."
"shit, that's boo radley."
A reference to the character of Boo Radley in the novel "To Kill a Mockingbird", a "Boo Radley moment" is when a person is astonished at the sight of something or someone excessively strange and/or rare.
(Seeing a recluse emerge from their home after a prolonged period of time)
Man: *stares blankly, mouth open*
Recluse: Having a Boo Radley moment, are we?