Noun
One who withdraws; one who takes back, or retracts.
Source: Webster's dictionaryAn Immobilizer can never be captured by a king or Withdrawer unless the variation popular in Cambridge is being played, in which case the Immobilizer itself must first be immobilized. Source: Internet
Capturing the Withdrawer with c4-d3 would result in stalemate, as black would then have no legal moves. Source: Internet
It might instead have captured the black Withdrawer with either d2-g5 or d2-h6. Source: Internet
Note that White could not play c4-d4, as that would place his own king in check from the black withdrawer. Source: Internet
The black withdrawer on e5 is not captured because pawns capture only vertically and horizontally, not diagonally. Source: Internet