To mark items on a list (with a checkmark or by crossing them out) that have been chosen for keeping or removal or that have been dealt with (for example, completed or verified as correct or satisfactory); to tick off (UK), tick (UK), cross off, strike off.
To carry out a decision recorded through the process of checking off an item on a list, including dealing with it, removing it from the possible choices, or removing the not checked items from further consideration.
To deduct union members' dues from their wages.
To show or manifest by symptoms; to point to as the proper remedies.
To point out; to discover; to direct to a knowledge of; to show; to make known.
To signal in a vehicle the desire to turn right or left.
To investigate the condition or power of, as of steam engine, by means of an indicator.