noun
Primarily used in the proverb 魚心あれば水心 (if a fish shows kindness, the water will too), meaning kindness begets kindness. Rarely used independently in modern Japanese.
See also: 魚心あれば水心
「魚心あれば水心」ということわざがある。
There is a proverb: 'If a fish shows kindness, the water will too.'
魚心という言
The word 魚心 is hardly used outside of the proverb.