Meaning of bastard cannon in English:

bastard cannon

noun

historical
  • A large cannon, having a bore of 7 inches (approx. 18 cm) in diameter and typically capable of firing projectiles weighing 41.25 pounds (approx. 18.7 kg), often listed in inventories of 17th- and 18th-cent. cannonry.

Origin

Early 17th century; earliest use found in John Smith.