Definition of left-hand rule in English:

left-hand rule

noun

Physics
  • A rule for finding the direction of motion of a current-carrying conductor in a magnetic field: the directions of the magnetic field, the current, and the force exerted on the conductor are indicated respectively by the first finger, second finger, and thumb of the left hand when these are held out perpendicular to each other; more fully "Fleming's left-hand rule".

Origin

Late 19th century; earliest use found in The Electrical Review.