Answer:
inveigh
Explanation:
Interloper: a person who's involved in a certain event, but they don't belong there and aren't wanted
Millennium: a period of 1000 years passing
Lassitude: state of lack of energy; languor
Inveigh: to speak with hostility; to attack in words
Intrinsic: naturally essential
Therefore, the answer is inveigh.
Have a lovely rest of your day/night, and good luck with your assignments! ♡
