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1.
The worst form of a sideman. Can be used for males and females.

Shows moistness, and overall the worst sideman behaviour. Usually leaves friends 'hanging'
"man, do you lift?"
"Yeah, I lift...my legs when I walk"
Sidebreast.

"wna come 2 the cinema 2day?"
"Nah, gotta expand my knowledge on land economy."
Sidebreast.

"spud me"
"..........nah"
Sidebreast.
by l337n3s5 March 11, 2013
 
2.
Noun: Classy breasts viewed from the side. Similar to sideboob, but of the highest quality. Can be clothed or un-clothed, but the outline of the breast must be clearly defined.

The finest source of this phenomenon is sidebreast.com

See also: sideboob, boobs
Her boobs look good enough to qualify as sidebreast. Yeah, did you see her sidebreast when she leaned over to get that pen?
by sideboober November 23, 2010