noun
maternal instinct
Refers to the innate drive in mothers to protect and nurture their offspring. Often used in psychological or everyday contexts.
彼女は母性本能が強いので、子供をとても大切にする。
She has a strong maternal instinct, so she takes very good care of her children.
Compound of 母性 (maternal nature) and 本能 (instinct). The exact historical derivation is uncertain, but the term is a straightforward modern coinage.