3 letters:
res, rol

4 letters:
bail, bale, cale, dail, dale, fail, gael, gail, gale, hail, hale, jail, kail, kale, mail, male, nail, pail, pale, race, rage, raid, rain, rake, rape, rase, rate, raul, rave, rays, raze, real, reel, rein, riel, rile, rill, roil, role, roll, rule, sail, sale, tail, tale, vail, vale, veil, wail, wale, yale, rail

5 letters:
calle, frail, gayle, grail, rails, raise, rathe, rayed, reign, shale, trail, whale

7 letters:
braille, they'll