Keywords: Go term
A new move is a move that was never played before in a given situation. In Go it is used for a play that deviates from current joseki but is a candidate for becoming joseki.
There is a well known motto of Kozo Masuda? (famous 9-dan shogi player): "Shinte issho" (lifelong quest for new moves).
Bob McGuigan: See the quote of Kikuchi in Old Mottos
Language note: In both Chinese and Japanese, 新 means new, and 手 means move.
 The equivalent jargon in the world of chess would be a Theoretical Novelty(TN).