Толковый словарь английского языка - pellicle

noun Etymology: Middle French pellicule, from Medieval Latin pellicula, from Latin, diminutive of pellis Date: 1541 a thin skin or film: as, an outer membrane of some protozoans (as euglenoids or paramecia), a film that reflects a part of the light falling upon it and transmits the rest and that is used for dividing a beam of light (as in a photographic device)