word \ multi \ castle \ oxy \ anthro \ hydro

oxy	anthro	hydro	castle
sharp, pointed	of or pertaining to human beings	water	a large and stately mansion a large building formerly occupied by a ruler and fortified against attack (chess) the piece that can move any number of unoccupied squares in a direction parallel to the sides of the chessboard interchanging the positions of the king and a rook