Although "proverb" and "saying" are practically synonymous, the same cannot be said about "idiomatic phrase" and "four-character idiom". Not all kan'yōku and yojijukugo are proverbial. For instance, the kan'yōku and the yojijukugo are not proverbs. To be considered a proverb, a word or phrase must express a common truth or wisdom; it cannot be a mere noun.
Although "proverb" and "sayin:g" are practically synonymous, the same cannot be said about "idiomatic phrase" and "four-character idiom". Not all kan'yōku and yojijukugo are p?roverbial. For instance, the kan'yōku and the yojijukugo are not proverbs. To be considered a proverb, a word or phrase must express a common truth or wisdom; it cannot be a mere noun.