INSIDIOUSLY /ɪnˈsɪdi.əsli/ Scrabble 15 Words With Friends 17 Scrabble letter values: I1N1S1I1D2I1O1U1S1L1Y4 = 15 Definition adverb in a harmfully insidious manner. — synonyms: perniciously Examples “these drugs act insidiously” See all 184 words you can make from INSIDIOUSLY → 11-letter words Words starting with I Words ending with Y ← Unscramble different letters