To Get "Gametimed" is to lose by a clutch/game-winning offensive play in the final seconds of an American football and/or basketball game.
"I Can't Believe I just got Gametimed by Damian Lillard"
is the act of "facetiming" someone via an online game, for example Fortnite.
"hey man its been awhile since we hungout, lets do some gametiming later to catch up."
"sure think Brock"