clot

array, assemblage, band, bank, batch, battery, block, bunch, clump, cluster, clutch, collection, constellation, group, grouping, huddle, knot, lot, muster, package, parcel, passel, set, suite

blob, chunk, clod, clump, dollop, glob, gob, gobbet, hunk, knob, lump, nub, nubble, nugget, wad

airhead, birdbrain, blockhead, bonehead, bubblehead, chowderhead, chucklehead, clodpoll (or clodpole), cluck, clunk, cretin, cuddy (or cuddie) [British dialect], deadhead, dim bulb [slang], dimwit, dip, dodo, dolt, donkey, doofus [slang], dope, dork [slang], dullard, dum-dum, dumbbell, dumbhead, dummkopf, dummy, dunce, dunderhead, fathead, gander, golem, goof, goon, half-wit, hammerhead, hardhead, idiot, ignoramus, imbecile, jackass, know-nothing, knucklehead, lamebrain, loggerhead [chiefly dialect], loon, lump, lunkhead, meathead, mome [archaic], moron, mug [chiefly British], mutt, natural, nimrod [slang], nincompoop, ninny, ninnyhammer, nit [chiefly British], nitwit, noddy, noodle, numskull (or numbskull), oaf, pinhead, prat [British], ratbag [chiefly Australian], saphead, schlub (also shlub) [slang], schnook [slang], simpleton, stock, stupe, stupid, thickhead, turkey, woodenhead, yahoo, yo-yo

block, choke, clog, congest, dam, gum (up), jam, obstruct, occlude, plug (up), stop (up), stuff

coagulate, congeal, gel, gelate, gelatinize, jell, jelly, set