means A person who belongs to the same team as you, working toward a shared goal.

from A transparent compound of "team" plus "mate." "Team" comes from Old English "team," which originally meant a set of draft animals harnessed together to pull a plow or wagon — a yoked group moving as one. "Mate" comes from Middle Low German "mate" or "gemate," a companion, literally one you share food with (a cousin of "meat" in its old sense of "food"). So a teammate is, at root, the one yoked beside you who also shares your bread — which the lunchtime roasting honors nicely.