The game of hide-and-seek. Also as interjection: the call used in the game.
‘All hid’ is used as a name for hide-and-seek in variants of the game in which that call is used by the seeker to ascertain whether all the other players have hidden, or by the hiders to inform the seeker that they are ready. The name is apparently attested earlier than hide-and-seek, and is found only in historical contexts in British English after 17th century.
Late 16th century; earliest use found in William Shakespeare (1564–1616), playwright and poet. From all [noun] + hid, past participle of hide.