astringent persimmon
Refers to a persimmon that is still astringent and inedible raw due to high tannin content; often contrasted with 甘柿 (sweet persimmon).
Astringent persimmons cannot be eaten as they are, so we make dried persimmons.
Standard kanji spelling.
Compound of 渋 (shibu, 'astringent') + 柿 (kaki, 'persimmon').