noun

an unintentional act or remark causing embarrassment to its originator; a blunder.

in my first few months at work I made some real gaffes

blunder,mistake,error,slip,indiscretion,impropriety,breach of etiquette,miscalculation,gaucherie,solecism,faux pas,lapsus linguae,lapsus calami,slip-up,howler,boo-boo,boner,botch,fluff,fail,boob,bloomer,clanger,blooper,bloop,goof,floater,fuck-up