1.
Yoel Steinberg asked:
Who is "Mashi'ach" quoted in Tosfos DH Amar?
Yoel Steinberg
2.
The Kollel replies:
It stands for "Mori she'Yicheh," -- "my mentor, may he live long," who is generally assumed to be Rabeinu Peretz. The phrase appears quite often in Tosfos in Makos (6-19), and in Tosfos in Meilah 18b as well.
M. Kornfeld