dullard, n. dolt, dunce, Inf. deadhead, blockhead, SI. dummkopf, oaf, clod; loggerhead, thickhead, Inf. chump, Inf. coot, Inf. dummy, SI. dodo, SI. dope, SI. dumbbell, SI. meatball or meathead; fathead, numskull, beetlehead, bonehead, dunderhead, dunderpate, chucklehead, SI. dumbhead, SI. lunkhead, SI. lard-head, Inf. knucklehead, SI. stupidhead; donkey, ass, SI. goon, lubber, lout; simpleton,. Simple Simon, sap-head, noodle, idiot, cuckoo, Inf. jay; idiot, Inf. moron, SI. retread, imbecile, mooncalf, lamebrain, dim-wit, nit-wit, half-wit, SI. zombie, goose; pinhead, SI. birdbrain, scatterbrain, SI. flake, rattlehead, rattlebrain, harebrain, SI. dingbat, SI. ding-a-ling, featherbrain, addle-brain, addle-head; fool, ninny, nincompoop, ninnyhammer, SI. yo-yo, tomfool; All SI. jerk, schmuck, boob, booby, noodle, nudnik, blubberhead; ignoramus, know-nothing, schlep, Inf. lightweight, lowbrow.
duly, adv. 1. in a due manner, properly, as is proper, seemly, suitably, fitly, fittingly, befittingly, as is fitting, rightly; becomingly, decorously.
2. in due season, in due time; regularly, punctually.
dumb, adj. 1. mute, speechless, silent, noiseless, soundless, mum, aphonic; voiceless, non-vocal, wordless, pantomimic; reticent, taciturn, quiet, uncommunicative, reserved, tongue-tied.
2. Informal, stupid, slow-witted, featherbrained, dull. See - dull (def. 1).
dumfound, v. astound, astonish, amaze, Inf. flabbergast, strike dumb, render speechless, dumfounder; stun, stagger, take aback, floor, shock, jar, jolt, Inf. bowl over, Inf. give [s.o.] a turn, Inf. catch [s.o.] up short; stupefy, petrify, paralyze, benumb, incapacitate; startle, surprise, disconcert; confuse, baffle, confound nonplus, perplex, embarrass, pose; bewilder, dazzle, electrify, Inf. take one's breath away; unbalance, disorient, Inf. catch off guard.
dumfounded, adj. astounded, amazed, astonished, Inf. flabbergasted, taken aback, floored, Inf. bowled over; stunned, shocked, startled, surprised, disconcerted, dazed, speechless, dumb, numb, paralyzed, frozen, petrified, incapacitated; confused, disoriented, baffled, confounded, nonplused, perplexed, bewildered; Inf. shaken, SI. shook, Inf. caught up short, Inf. caught off guard, Inf. thrown for a loss, SI. knocked for a loop.