THERMIONICS Scrabble 18 Words With Friends 20 Scrabble letter values: T1H4E1R1M3I1O1N1I1C3S1 = 18 Definition noun the branch of electronics dealing with thermionic phenomena (especially thermionic vacuum tubes). See all 992 words you can make from THERMIONICS → 11-letter words Words starting with T Words ending with S ← Unscramble different letters