Verb (5-dan, す, transitive)
1. to accomplish; to achieve; to carry out; to fulfill; to fulfil; to realize; to execute; to perform; to do
しかし約束した以上、果たさなければならない。However, since I have made a promise, I must fulfill it.
Auxiliary verb (5-dan, す)
2. to do ... completely; to do ... entirely
after the -masu stem of a verb