Similar to a broner, which is an erection caused by hearing one of your male friends, or "bros" relay a story of a recent
sexual conquest, a round of golf or a
particularly tasty beer, but is an erection caused by a similar story told by a female friend or "gal-pal". Hence, groner
Normally a groner is caused by the
description of non-sexual activity between your gal-pal and one or more of her female friends that, when pictured by a healthy, heterosexual male, causes blood to flow to the nether-regions, triggering a groner or even a massive groner for a really good story involving with insinuated "girl on girl" action.
"Dude, my friend Susie was telling me about how she recently got a
Brazilian bikini wax and how her best friend had to see how it looked so she just dropped trou and showed off the whole works... I got a total groner and had to un-tuck my shirt just to cover it up... cool story but totally
embarrassing!"
(Please note, that relaying a story about the
circumstances that caused your groner to one of your male friends may cause him to have a broner or, what is otherwise known as a "second-degree groner")