Definitions:
a covering for all or part of the face, worn as a disguise, or to amuse or frighten others.

a covering worn over the mouth and nose in order to reduce the transmission of infectious agents, or to prevent the inhalation of pollutants and other harmful substances.

a face pack

a likeness of a person's face moulded or sculpted in clay or wax.

a manner or expression that hides one's true character or feelings

a piece of material such as card used to cover a part of an image that is not required when exposing a print.

a patterned metal film used in the manufacture of microcircuits to allow selective modification of the underlying material.

the enlarged labium of a dragonfly larva, which can be extended to seize prey.

cover (the face) with a mask

conceal (something) from view

cover (an object or surface) so as to protect it during painting