Antonyms are opposite, what is "reverse"?

[Glizdka]

Hello, I can't seem to find the word that describes something very similar to what antonyms do.
Antonyms are words that are opposite.
"I am happy." → "I am not happy." → "I am sad."
What word has the reverse meaning? In the examples below, the word I mean is in bold.


-Would you like ketchup or mustard?
-Neither → Not either → Either.

-Would you like ketchup or mustard?
-Neither → Both are not wanted → Both.


Have you never wanted...?
Have you ever wanted...?
Have you always wanted...?


Believe nothing he says.
Don't believe anything he says.
Don't believe everything he says.

I gave it to him.
I took it from him.
I got it from him.

 

[jutfrank]

Let me begin to help you think about this by sketching out two different kinds of antonymy.

1) Binary antonyms

true/false
male/female
dead/alive
on/off

These are word pairs where the sense of one entails the sense of the other. The sense of 'dead' is 'not alive' and the sense of 'alive' is 'not dead'. Logically, there are no other possibilities. Something is either dead or alive—there's no third option.

Many philosophers have asked 'Why is there something rather than nothing?'

In the above sentence, the bolded words are binary antonyms.


2) Converses

above/below
grandparent/grandchild
bigger than/smaller than
borrow/lend

These are words that describe a relationship between two things. Logically, we know that if X is bigger than Y, then Y is smaller than X. Similarly, if I am your grandchild, then you must be my grandparent.

I gave him the key.
He took the key from me.

In the sentences above, the two bolded words are converses.

 

[Glizdka]

This is precisely what I was looking for, thank you!

 

[Tarheel]

G, you have a comma splice there.