Stop
Stops playback on the specified/assumed/elicited player.
Reminder: It's 'Alexa, tell MediaServer to Stop' and not 'Alexa, Stop'.
Invocation options (choose based on grammar-fit):
Alexa, [ open / start / launch ] MediaServer [ and ] …
Alexa, [ tell ] MediaServer [ to ] …
Alexa, [ ask ] MediaServer [ to / for / if / about ] …
Alexa, [ get ] … [ from / using ] MediaServer
Alexa, … [ from / using ] MediaServer
In place of '…', fill in one of the options below:
stop playback
stop playback for the {Player}
stop playback for the {Player} player
stop playback from the {Player}
stop playback from the {Player} player
stop playback in the {Player}
stop playback in {Player}
stop playback on the {Player}
stop playback on the {Player} player
stop playback on {Player}
stop playback on {Player} player
stop the {Player}
stop the {Player} player
stop {Player}
terminate
terminate playback