Counterclockwise

Counterclockwise adverb and adjective meaning the opposite of clockwise. That is, counterclockwise is a rotation to the left and up, a direction opposite the rotation to the right and down of a typical wall clock's hands. Counterclockwise is also sometimes called widdershins.

Typically, screws and bolts are loosened counterclockwise and tightened clockwise. One mnemonic for remembering this is "righty-tighty, lefty-loosey" (right to tighten, left to loosen.)

Occasionally, clocks whose hands revolve counterclockwise are sold as a novelty.

In trigonometry, an angle in standard position is measured counterclockwise from the x-axis.