One Word Substitution

Inflammable means capable of being easily set on fire. Don't confuse it with infallible (incapable of being wrong), inimitable (too unique to copy), or insoluble (cannot be dissolved).

Congregation specifically means a group of people assembled for religious worship. Assembly is any gathering, audience are spectators or listeners, and crowd is a large group without specific purpose.

Antique means existing since old times or dating from an earlier period. Animate means alive, edible means edible, and feminist relates to women's rights - none fit the meaning.

Insolvent specifically means unable to pay debts. Panacea is a cure-all, invincible means unbeatable, and sinecure is a paid position with little work.

 One who believes everyone is credulous.

Monarchy is government by a king, queen, or monarch. Autocracy is rule by one person (not necessarily royalty), oligarchy is rule by a small group.

Inexplicable means something that cannot be explained or accounted for. Improbable means unlikely, inimitable means unique/unequalled, and doesn't fit.

Inaudible means unable to be heard. Booming means loud, insolvent means unable to pay debts.

Homicide is the killing of one person by another. Regicide is killing a king, patricide is killing one's father, and fratricide is killing one's brother.

Voluntarily means of one's own free will or by choice. Obligatory means required, essential means necessary.

Polyandry refers to the practice of a woman having multiple husbands simultaneously. Polygamy is a broader term that can mean multiple spouses of either gender, while monogamy means having only one spouse. The key distinction is that polyandry specifically involves one wife with multiple husbands.

Monogamy is the practice of being married to only one person at a time. Bigamy is marrying a second person while still legally married to the first (illegal in most jurisdictions). The question asks for marrying only one person, making monogamy the correct answer.

 One someone takes a side, he or she is partial to that side. Hence, 'taking sides' is partiality.

An antiseptic is a substance that prevents or stops the growth of microorganisms that cause putrefaction (decay/rotting). Antiseptics are used to clean wounds and prevent infection. Eligible means qualified, egoist refers to self-centered behavior, and fatalist believes in destiny.

 When there is no rain, it is a drought.