お父さん
おとうさん · otousan · JLPT N5 · noun
father
👨 お + 父 (father) + さん: honorific o + father + Mr. = respected father
The core is 父 (father), read tou here. お is a politeness prefix and さん is the same respectful suffix used after names. Sound hook: otousan starts like oh-toe, so think oh, toe-san, Mr. Toe the dad. Used for someone else's father or to address your own.