To copy/duplicate or confirm that two things are the same, in the past tense. Can also be used as a general acknowledgment.
"Did you get that report done?" ... "Yep, I looked at Lisa's and just samed it."
"Hey bro, I just watched that vid of Susan Boyle on youtube."... "Samed. Watched it two days ago."
"I love your mom's cooking."... "Samed."