godan verb (-su), transitive verb
Physical sense: to melt a solid into a liquid or soften it, often with heat. Used for metals, fats, cheese, etc.
バターをフライパンでとろかす。
Melt butter in a frying pan.
高温で鉄を蕩かす。
Melt iron at high temperature.
godan verb (-su), transitive verb
melt someone's heart; disarm emotionally
Figurative sense: to soften someone's feelings, make them relent, or win them over with charm or kindness. Often used with 心 or 気持ち.
彼女の笑顔が彼の心をとろかした。
Her smile melted his heart.
その優しい言葉で彼の怒りが蕩かされた。
His anger was disarmed by those kind words.