1. faction / fiction / factitious / fictitious

faction: A faction is an organized group of people within a larger group, which opposes some of the ideas of the larger group and fights for its own ideas.

e.g. A peace agreement will be signed by the leaders of the country’s warring factions.

factitious: produced by humans rather than by natural forces

fictitious: Fictitious is used to describe something that is false or does not exist, although some people claim that it is true or exists.

2. calamity / calumny

calamity: A calamity is an event that causes a great deal of damage, destruction, or personal distress. (FORMAL)(=disaster)

calumny: Calumny or a calumny is an untrue statement made about someone in order to reduce other people’s respect and admiration for them. (FORMAL)(=slander)(污蔑，诽谤(的话))

3. team / teem

teem: If you say that a place is teeming with people or animals, you mean that it is crowded and the people and animals are moving around a lot. (=swarm)

4. callow / callous

callow: A callow young person has very little experience or knowledge of the way they should behave as an adult.

callous: A callous person or action is very cruel and shows no concern for other people or their feelings.

5. contrite / contrive / connive

contrite: If you are contrite, you are very sorry because you have done something wrong. (FORMAL)(= apologetic)

contrive: If you contrive to do something difficult, you succeed in doing it. (FORMAL)

connive: If one person connives with another to do something, they secretly try to achieve something which will benefit both of them.

6. discrete / discreet

discrete: Individually separate and distinct:

discreet: Careful and prudent in one’s speech or actions, especially in order to keep something confidential or to avoid embarrassment:

7. impressive / impressionable

impressionable : easily influenced