reciprocating

(без степеней сравнения)That moves back and forth or up and down.

(без степеней сравнения)Of an engine type, that has one or more pistons that move back and forth or up and down.

(без степеней сравнения)Of an other machine, whose mechanism relies on a back and forth or up and down motion.

(без степеней сравнения)Of a person or their actions, responding in kind.

reciprocating behavior