(n.) The egg of a louse or other small parasitic insect\.

adverse criticism animadversion aspersion bad notices bad press captiousness carping cat flea cavil caviling censoriousness chigoe cockroach crab criticism dog flea exception faultfinding flak flea grayback hairsplitting hit home thrust hostile criticism hypercriticalness hypercriticism imputation jigger knock louse mite nagging nay niggle niggling nit-picking nix no nope obloquy overcriticalness parasite pestering pettifogging priggishness quibble quibbling rap red bug reflection reproachfulness roach sand flea slam stricture swipe taking exception trichoschistism vermin weevil