Definition of tappet in English English dictionary
A lever or projection which is moved by some other piece, as a cam, or intended to tap or touch something else, in order to produce change or regulate motion
A lever or projection moved by some other piece, as a cam, or intended to tap or touch something else, with a view to produce change or regulate motion
{i} projection on a moving part designed to touch and move or be moved by some other part at certain intervals (Machinery)