What is "right-handed screw"

Right-handed \Right"-hand`ed\, a.

1. Using the right hand habitually, or more easily than the left.

2. Having the same direction or course as the movement of the hands of a watch seen in front; -- said of the motion of a revolving object looked at from a given direction.

3. (Zo["o]l.) Having the whorls rising from left to right; dextral; -- said of spiral shells. See Illust. of Scalaria.

   Right-handed screw, a screw, the threads of which, like those of a common wood screw, wind spirally in such a direction that the screw advances away from the observer when turned with a right-handed movement in a fixed nut.