When a woman hits someone with her
tits. It is roughly the
female equivalent to a mushroom stamp. The root
word 'milk' comes from the female mammary glands (i.e. breasts) ability to produce milk.
"She knocked my glasses off my face with her
tits when she gave me that milkstamp"
"She has huge
tits, so she gives great milkstamps"
"Will you tell your
mom to stop milkstamping the neighbors with that giant rack of hers?