投筆從戎

投笔从戎
tóubǐcóngróng
  1. to lay down the pen and take up the sword (idiom)
  2. to join the military (esp. of educated person)

CEDICT

  1. (of a scholar) to join the military
  2. to join the military

Wiktionary

漢代班超因家貧而常為官傭書以供養，後輟業而嘆：「大丈夫無它志略，猶當效傅介子、張騫立功異域。」典出《後漢書．卷四七．班超傳》。後指棄文從軍以衛國建功。

重編國語辭典

放棄文化工作而從軍

維基詞典

Entry Composition

1 投筆 tóubǐ
  1. (literary, figurative, of a writer) to cease writing; to forsake the pen (for something else)
  2. to cease writing; to forsake the pen (for something else)
2 從戎 cóngróng
  1. to enlist
  2. to be in the army