warm the cockles of someone's heart
17th century, Unknown, possibly due to resemblance of cockles to hearts. Alternatively, may be corruption of Latin cochleae in cochleae cordis (“ventricles of heart”), or of Irish Gaelic origin. Possibly also inspired by mollusks opening when exposed to warmth, notably cooking.
- (idiomatic) To provide happiness, to bring a deeply-felt contentment
- (to provide happiness): warm someone's heart