Unscrambling STUPID gives 55 words. STUPID is the longest, and STUPID scores the most at 9 points.
No other single word uses all 6 letters of STUPID. STUPID has 6 letters: 2 vowels and 4 consonants, worth 9 points before any board bonuses.
6-letter words 1
5-letter words 2
duits6situp7
4-letter words 17
dips7dipt7dits5duit5dups7dust5pits6psid7puds7puts6spit6spud7stud5suit4tips6tuis4tups6
3-letter words 24
dip6dis4dit4dui4dup6ids4its3pis5pit5piu5psi5pud6pus5put5sip5sit3sud4sup5tip5tis3tui3tup5ups5uts3
2-letter words 11
id3is2it2pi4ps4si2ti2ts2up4us2ut2
Words are from our open word list and include some game-only words. Rude words are left out of this page; the unscrambler shows every valid word, lets you add blank tiles and filter by length.