2 letters:
ct

3 letters:
cor, cos

4 letters:
coar, cohr, cora, cord, core, cork, corl, corn, corp, corr, cort, cory, coss, kohr, kora, korb, korf, korn, kort, kory, koss

5 letters:
borse, carse, chord, cohrs, cores, corey, corks, corne, corp., corps, corry, corsi, corso, corte, court, coury, force, forse, horse, kaori, kautz, kohrs, korey, korff, korry, korte, korth, kortz, morse, morss, norse, sorce, vorce

6 letters:
bourse, chorus, corp's, corps', corpse, corrao, corrie, corrow, corser, cortes, coughs, courts, hoarse, nourse, source, coarse, course

7 letters:
coarser, corp.'s, courser, coursey, court's, courts', 'course