PSI /psaɪ/ ► audio Scrabble 5 Words With Friends 6 Scrabble letter values: P3S1I1 = 5 Definition noun a unit of pressure. — synonyms: pounds_per_square_inch noun the 23rd letter of the Greek alphabet. Anagrams of PSI pissip See all 6 words you can make from PSI → 3-letter words Words starting with P Words ending with I ← Unscramble different letters