had been exterminating

• past perfect progressive

  past perfect progressive

  Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.

  of exterminate.
  exterminate

  verb (used with object)

  to get rid of by destroying; destroy totally; extirpate.

Related Words

• annihilate
• decimate
• eradicate
• extinguish
• obliterate
• slaughter
• stamp out
• wipe out