adjective

lacking interest or excitement.

your diet doesn’t have to be dull and boring

uninteresting,boring,tedious,tiresome,wearisome,dry,dry as dust,flat,bland,characterless,featureless,colourless,monotonous,unexciting,uninspiring,unstimulating,lacking variety,lacking variation,lacking excitement,lacking interest,unimaginative,uneventful,lifeless,soulless,insipid,unoriginal,derivative,commonplace,prosaic,run-of-the-mill,humdrum,unremarkable,banal,lame,plodding,ponderous,pedestrian,dull as dishwater,deadly,no great shakes,not up to much,dreich,dullsville,ornery

verb

make or become dull or less intense.

time dulls the memory

lessen,decrease,diminish,reduce,dampen,depress,take the edge off,blunt,deaden,mute,soften,tone down,allay,ease,soothe,assuage,alleviate,palliate,moderate,mitigate,numb,benumb,desensitize,render insensitive,stupefy,daze,stun,drug,sedate,tranquillize,narcotize,torpefy,obtund,fade,pale,bleach,wash out,decolorize,decolour,dim,etiolate,darken,blacken,blur,veil,obscure,shadow,fog,bedim,put a damper on,cast a pall over,cast down,lower,crush,shake,sap,suppress,extinguish,smother,stifle