The word "helicopter" can be replaced with various synonyms depending on the context. Some of the synonyms for "helicopter" include chopper, whirlybird, rotorcraft, copter, and eggbeater. Each of these words describes the same type of aircraft that achieves lift and propulsion through the rotation of its rotors. In informal settings, "chopper" and "whirlybird" are commonly used to refer to helicopters. "Rotorcraft" is a more formal term, often used in technical writing. "Copter" is a shortened version of "helicopter" and is often used in advertising or branding. Lastly, "eggbeater" is a slang term that refers to the sound of a helicopter's rotors. Overall, there are various words that can be used interchangeably with "helicopter" to add variety and creativity to writing.