Answer: strangest

AnswerCrossword Clue
STRANGESTLeast familiar
strangestHaving a nonzero value for strangeness
strangestNot previously visited, seen, or encountered; unfamiliar or alien
strangestUnaccustomed to or unfamiliar with
strangestUnusual or surprising in a way that is unsettling or hard to understand
strangestSTRANGE, unusual (not usual)