berks(British), boobies, charlies(also charleys, British), cuckoos, ding-a-lings, dingbats, ding-dongs, doofuses(also dufuses, slang), featherheads, fools, geese, gits(British), half-wits, jackasses, lunatics, mooncalves, nincompoops, ninnies, ninnyhammers, nits(chiefly British), nitwits, nutcases, nuts, simpletons, simps, turkeys, yo-yos

daredevilsmadmen, madwomenairheads, birdbrains, blockheads, dodoes(or dodos), dolts, donkeys, dopes, dorks(slang), dumbbells, dummies, dunces, fatheads, ganders, goons, half-wits, idiots, ignoramuses(also ignorami), imbeciles, know-nothings, knuckleheads, morons, numskulls(or numbskulls), pinheads, schlubs(also shlubs, slang), schlumps(slang), schnooks(slang), stocksfeatherbrains, scatterbrainsbutts, dupes, laughingstocks, mockeries, monkeyschumps, losers, schlemiels(also shlemiels)characters, codgers, crackbrains, crackpots, cranks, kooks, oddballs, screwballs, weirdos