Acronym for "Hard On For Specific Reason." Used to describe an erection that has been triggered through sexual arousal, or stimulation.

Opposite: HOFSR; Acronym for "Hard On For No Reason."
"Dude, cover your HOFNR"

"Did you see Jessica's new thong? I'm definitely sporting a HOFSR"
by Ecclesies December 13, 2011
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