As Jungho Nam mentioned above, it means EVENTFUL.
다사 (多事): 여러 가지 일이 많음 eventfulness; being busy
다난 (多難): 어려움이 많음 many difficulties; lots of trouble
다사 다난한 (한) 해였다
I had one difficulty after another that year.
작년에 내외로(literally in and out;both at home and abroad) 다사 다난한 한 해였다
Last year was a very eventful one both at home and abroad.