siege gun
  攻城炮
  Siege n.
  1. A seat; especially, a royal seat; a throne. [Obs.] “Upon the very siege of justice.”
  A stately siege of sovereign majesty,
  And thereon sat a woman gorgeous gay.   --Spenser.
  In our great hall there stood a vacant chair . . .
  And Merlin called it “The siege perilous.”   --Tennyson.
  2. Hence, place or situation; seat. [Obs.]
     Ah! traitorous eyes, come out of your shameless siege forever.   --Painter (Palace of Pleasure).
  3. Rank; grade; station; estimation. [Obs.]
  I fetch my life and being
  From men of royal siege.   --Shak.
  4. Passage of excrements; stool; fecal matter. [Obs.]
     The siege of this mooncalf.   --Shak.
  5. The sitting of an army around or before a fortified place for the purpose of compelling the garrison to surrender; the surrounding or investing of a place by an army, and approaching it by passages and advanced works, which cover the besiegers from the enemy's fire. See the Note under Blockade.
  6. Hence, a continued attempt to gain possession.
     Love stood the siege, and would not yield his breast.   --Dryden.
  7. The floor of a glass-furnace.
  8. A workman's bench.
  Siege gun, a heavy gun for siege operations.
  Siege train, artillery adapted for attacking fortified places.