[しゃす, shasu] (v5s) (1) (See 謝する) to thank; (2) to apologize; to apologise; (3) to say farewell; to retreat; to retire; (4) to refuse; (5) to pay back; to settle old scores
[しゃする, shasuru] (vs-s) (1) to thank; (2) to apologize; to apologise; (3) to say farewell; to retreat; to retire; (4) to refuse; (5) to pay back; to settle old scores