Here's what rhymes with flabbergast.
cast caste aghast last passed past fast vast hast classed mast amassed massed blast surpassed harassed overcast recast repast unsurpassed enthusiast Words that almost rhyme with flabbergast
gasp craft grasp laughed shaft dashed graft clasp crashed lashed raft clashed mashed draft draught flashed smashed staffed slashed photographed splashed telegraphed handicraft mimeographed cat cant capped gasped canst that fact sat attached attacked fat grant hat packed rat adapt backed glanced grasped lacked matched wrapped bat chat cracked danced mapped mat pact shalt tact tapped taxed camped chanced chant clapped clasped hatched masked pat scant thatched waxed hacked lapsed patched racked rapt sacked tacked tat vat advanced plant exact flat attract tract collapsed detached react trapped elapsed habitat ranked snapped snatched thanked artifact clamped cramped enact scratched slant slapped spat stacked tracked banked damped smacked stat yanked impact abstract enhanced intact interact relaxed despatched dispatched financed handicapped stamped branched encamped flanked caveat democrat detract overlapped relapsed retract strapped supplant transact extract counteract diplomat distract implant subtract aristocrat thermostat transplant