4 letters:
ceco, saco, saki, sako, seco, seki, seko, sica, soco, suki

5 letters:
cerca, cerco, cicco, cieco, circa, circo, psyco, sacai, sacar, sacca, sacco, sacre, saeco, saiki, saiko, saker, sakha, sakko, sawka, seaco, secar, secca, secco, secor, secoy, secre, seiki, seiko, seker, serca, serco, sicca, sicko, sicky, siker, sikha, sircy, sirko, soaky, socca, socco, socko, socky, socoh, sojka, sokar, sokka, sooky, souci, soyka, so co, su-ki, succo, sucka, sucky, sucre, sukey, sukha, sukie, sukka, sukur, surco, sycco, syker, tsuki

6 letters:
cecchi, psyche, psycho, sacchi, sachar, sacher, sacker, sake i, seacow, secchi, seeker, seek a, siccar, sicher, sicker, sickie, sick o, sikhye, soaker, soccer, sochor, socker, sookie, soucie, succah, succor, sucker, suckow, sueker, sukhoi, sukkah, sukkar, sukker, sukkot, su chi, sychar

7 letters:
psycho-, sacchar, sea-cow, sea cow, sir kay, sockeye, sow cow, sue coe

8 letters:
sacchar-, seek her