A form of greeting used by a red-headed fuck where s/he, upon arrival, either gives you a jolly "hello" and/or exposes his or her genitals to you. These are the ONLY two options.
Either option is definitely perceived as offputting and unenjoyable.
Gary: Ugh... P Dawg gave me the old gingerhello when he showed up at the party last night.
A loss of self control followed by extreme destruction and violence that only a ginger can possess. Often times brought on with no provoking, and without any kind of warning signs.
"Oh shit here comes a ginger don't look it in the eyes."
"Why not?"
"Them gingers are crazy and unpredictable let alone that there is nothing worse then ginger rage.