an oblong shield made of boards or wickerwork covered with leather, with sometimes an iron rim; -- carried chiefly by the heavy-armed infantry.-a penthouse or awning.-the second and largest of the four parts forming the upper surface of a thoracic segment of an insect. it is preceded by the prescutum and followed by the scutellum. see the illust. under thorax.-one of the two lower valves of the operculum of a barnacle.