同/近义词: animosity, enmity, hostility, malevolence
反义词: amity, affinity, alliance, association

enmity, enemy

hostility, hostile, hospitality(好客)

malevolence, malevolent, malicious, benevolence, benevolent(kind and generous)

LDOCE把malicious解释为very unkind and cruel, and deliberately behaving in a way that is likely to upset or hurt sb. 另据Merriam-Webster: having or showing a desire to cause harm to sb; given to, marked by, or arising from malice.

例句[LDOCE/柯林斯]:
1. Microsoft generally releases Windows Malicious Software Removal Tool (MSRT) monthly as part of Windows Update or as the standalone tool.
2. A malevolent person wants to harm other people. =evil
3. A malevolent person deliberately tries to cause harm or evil. ≠benevolent

总结：形容人时用malevolent。

amity, amiable, amiability

https://www.wordhippo.com/what-is/the-adjective-for/affinity.html

和affinity有关的形容词都很偏：affine, affinal, affinitive, affinitative

例句: It is well known that the acidity of the sulfate catalyst is affinitive to its calcination [煅烧] temperature.