お父ん is read as おとん (oton) and means dad.
おとん
oton
おとうさん
husband
おじいさん
grandfather
とうさん
father
おとうさま
ちち
ふぼ
father and mother
ふし
father and child
ちちのひ
Father's Day (3rd Sunday of June)
そぶ
おじ
uncle
ちちおや
おやじ
grizzly bear