Some nouns, not all, have opposites.
Noun opposites are called antonyms. Examples:
There is no postie of a koala. Nouns generally do not have opposites.
Nouns don't have opposites.
Finger is a noun. Nouns don't have opposites or antonyms.
Names, as proper nouns, do not have opposites. The meaning of a name may have.
There are no antonyms for nouns, but the word "sedan" might work.
Nouns describing objects do not have opposites. "Unncumbered" is the opposite of "burdened" (if by luggage you mean something that is a burden)
There is no such thing. It makes sense to talk about opposites of simple properties (adjectives), such as "fast", "clever", etc.; in general, it doesn't make so much sense to talk about the opposites of objects (nouns).
Some words do not have opposites. Generally those that do have opposites are adjectives or adverbs (fast vs. slow, rich vs. poor). Nouns often do not have opposites (e.g. there is no opposite for apple, steak, wine bottle). Girl follows that case. A girl is not the opposite of a boy. A girl is a young female human being, a boy is a young male human being. They are only different in one of the adjectives used to describe them, this does not make them opposite.
much is always used with uncountable nouns or nouns that cannot take (s)
"Pant" is a common noun. Pronouns are nouns that take the place of other nouns. They are: I, you, it, she, he, we, and they.
widower female-male just add er widow- widower
An antonym is an opposite, and while reptiles and amphibians are very different they can't be considered opposites because not every aspect of them are opposites. For example, there are both reptiles and amphibians that lay eggs. Generally, there are no antonyms for nouns (objects/organisms). Antonyms are most often used with adjectives, adverbs and verbs. Ex: dirty/clean