As a proper noun scutum
is (constellation) a small autumn constellation of the northern sky, said to resemble a shield it lies between the constellations of aquila, sagittarius, and the tail of serpens.
As a noun scutellum is
any of several shield-shaped structures in insects, grasses etc.
(historical, Roman antiquity) An oblong shield made of boards or wickerwork covered with leather, with sometimes an iron rim; carried chiefly by the heavy-armed infantry of the Roman army.
(zoology) A scute.
(zoology) One of the two lower valves of the operculum of a barnacle.
(obsolete) A penthouse or awning.
Any of several shield-shaped structures in insects, grasses etc
# (lichenology) A rounded apothecium having an elevated rim formed of the proper thallus, the fructification of certain lichens.
# (zoology) The third of the four pieces forming the upper part of a thoracic segment of an insect. It follows the scutum, and is followed by the small postscutellum.
# (zoology) One of the transverse scales on the tarsi and toes of birds.