donor; benefactor; almsgiver
chief mourner
client (of a builder, etc.)
彼が寺の施主となった。
He became the temple's benefactor.
新しい鐘には施主の名前が刻まれた。
The donor's name was engraved on the new bell.
裕福な商人が寺院修復の主要な施主を務めた。
A wealthy merchant served as the principal benefactor for the temple's restoration.