Answer: rud

AnswerCrossword Clue
RUDPresident Hayes' nickname
RUDRed ocher: Dial.
RUDSteering blade: Abbr.
RUDCarplike fish: Var.
RUDHari ..., Asian river
RUDCarplike fish
RUDHari ..., river in Afghanistan
RUDSteering mech.
rudto redden (to become red (the colour of blood, also REDD))
ruda freshwater Eurasian cyprinid fish (Scardinius erythrophthalmus) resembling the golden shiner