What is Hand Sandwich?
1.
The handshake for which the shaker, sandwiches the shakee's hand between his/her two hands, the shaker tilts his/her head, and says something comforting.
John's dad just got hit by a car, so I gave him a comforting hand sandwich.
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2.
When you rub a girl's vagina with your hand outside of the her underwear, but inside her pants.
"I couldn't finger her because her parents were in the front seat. So I just gave her a hand sandwich."
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3.
n., when you have all of the ingredients for a sandwich, except bread, so you just eat the components out of your hand
I just took a giant hit from the bong and got the munchies, but the bread was moldy, so I had to eat a hand sandwich.