(transitive) To spin (a ball) with this motion. / (music) To play a section of a record in reverse, as a disc jockey; to apply spinback.

Alternative form of back-seat driver.

(physics) The deflection of particles and/or radiation through angles greater than 90 degrees to the original direction of travel. / The particles and/or radiation deflected in this manner.

To scatter particles and/or radiation back to the direction from which they come.

present participle of backscratch

A scratch on the back.

To scratch one's or another's back. / (business, politics, slang) To engage in a reciprocal action.

A staircase at the rear of a building or one normally only used by servants and tradesmen. / An indirect or furtive means of access or intercourse.

Secret or furtive. / Scandalous.

(baseball) The rotation of the knee and lower body of the side of the batter away from the pitcher during a swing.