adverb
Indicates that something will happen in the near future, often used in a slightly old-fashioned or literary tone. Similar to そのうち or まもなく.
追っ付け雨が降り出すだろう。
It will start raining before long.
追っ付けお便りします。
I will write to you soon.
Derived from the verb 追っ付く (おっつく), meaning 'to catch up' or 'to be in time', with the adverbial form indicating something that will happen soon or in due course.