The act of pressing ones cheeks against another persons clothes or skin(preferably the skin) and leaving behind a small or large amount of smeared shit.
“Woah bro, you left a shit stain on my shirt when you were drunk yesterday. I can’t believe you stamped me”.
When during a competition, you allow your competitor to take the lead for a period of time until you near the end, when you pull ahead for the win right at the last moment.
I really thought he was going to win that leg of the run, until he got stamped by the other guy who darted ahead of him at the end.