3 letters:
sac, sak, sax

4 letters:
aker, akre, sack, sacs, saks, saxe

5 letters:
acker, makar, sacca, sacco, sachs, sacks, safir, saker, sater, saxer, secor, sucre

6 letters:
backer, bakker, hacker, lacher, macher, packer, racker, sachs', sacked, sadder, saffer, sanger, sanker, sanner, sapper, sasser, sather, sathre, satter, seeker, sicker, soccer, sochor, succor, sucker, sueker, tacker, wacker, zacher

7 letters:
lacquer, sackler, satcher, slacker, stacker, thacher, thacker, thakkar

8 letters:
schacher