ground ball, groundball, grounder, hopper - (baseball) a hit that travels along the ground

tooth - hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense

vane, blade - flat surface that rotates and pushes against air or water

cargo helicopter - a helicopter that carries cargo

heavier-than-air craft - a non-buoyant aircraft that requires a source of power to hold it aloft and to propel it

landing skids - the landing gear of a helicopter

rotor - rotating mechanism consisting of an assembly of rotating airfoils; horizontal rotors on a helicopter or compressor rotors of a jet engine

shuttle helicopter - a helicopter that shuttles back and forth

single-rotor helicopter - a helicopter having a single rotor

skyhook - helicopter carrying a reel of steel cable that can be used to lift and transport heavy objects

knife - edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle