The act of stealing packages from peoples' homes (i.e. porch piracy) during the holiday season. People often partake in grinching to avoid spending their own money on costly Christmas gifts.
A: Hey man, what presents did you buy for your family this year?
B: I didn't buy shit. I'm going grinching around the neighborhood this week.
Having a large, surprising erection from a penis of below-average size.
The term is derived from the climax of Dr. Seuss’s How The Grinch Stole Christmas: “And what happened, then? Well, in Whoville they say — that the Grinch’s small heart grew three sizes that day.”
“That ho was so fine, I was grinching before we even got back to her dorm!” Xander exclaimed, “it was about time to I laid the rumors of my small dong to rest.”