The letters in EITHER make 39 words of two letters or more. The longest is EITHER at 6 letters, and the highest-scoring is EITHER at 9 points.
No other single word uses all 6 letters of EITHER. EITHER has 6 letters: 3 vowels and 3 consonants, worth 9 points before any board bonuses.
6-letter words 1
5-letter words 6
ether8ither8retie5their8there8three8
4-letter words 10
heir7here7hire7rete4rite4thee7thir7tier4tire4tree4
3-letter words 14
ere3ert3eth6her6het6hie6hit6ire3ree3rei3ret3tee3the6tie3
2-letter words 8
eh5er2et2he5hi5it2re2ti2
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.