dunce

n person, esp a pupil, who is stupid or slow to learn （在学习上）愚笨的或迟钝的人（尤指学生）.

dully, duly, dumb, dumb show, dumb waiter, dumb-bell, dumbfound (also dumfound), dumbly, dumbness, dumdum, dummy, dummy run, dump, dumper, dumpiness, dumping, dumpling, dumps, dumpy, dun, dunce's cap, dunderhead, dune, dung, dungarees, dungeon, dunghill, dunk, duo, duodecimal, duodenal, duodenum, duologue, dupe, duple time, duplex, duplicate, duplication, duplicator, duplicitous,