Anything used to conceal something undesirable or that one does not want to be discovered.
A leaf of the fig plant.
A representation of leaf of a fig plant used to cover the genitals of a nude figure in a work of art (alluding to Genesis iii 7, in which Adam and Eve use fig leaves to hide their nakedness).
A clue, information, argument etc. that is or is intended to be misleading, diverting attention from the real answer or issue.
A herring that is cured in smoke and brine strong enough to turn the flesh red; a type of kipper.
A red herring prospectus.