Answer: stagiest

AnswerCrossword Clue
STAGIESTMost histrionic
STAGIESTMost artificial
STAGIESTMost theatrical.
STAGIESTTops in tacky theatrics
stagiesttheatrical; unnatural
stagiestof, pertaining to, or suggestive of the stage
stagiestSTAGY, having a theatrical quality, also STAGEY