Slang for being conceited, full of yourself, or to not be as good as you think you mite be.
Common usage:

"Man, that group in the studio last nite was smellin-themselves, they thought they shit was hot or somethin'."

"Them A**-Holes was smellin' themselves hard, couldn't get over it, like they smell was captivating' or some shit."

"Watch it now, don't be smellin' yourself now while you out there, your smelf mite be irreconcilable, take over ya."

**Any application of the phrase close to this usage is appropriate.**
by Javier Consuelo February 9, 2013
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