Choose the perfect synonym or antonym for the word

Either

/ˈaɪðər/

Used to indicate one or more possibilities, choices, or conditions.

Synonyms:

You mustn't let that child make that noise either.

And yet without a word on either side.

I have never seen either Mr. or Mrs. Elton.

From Old English ægther, meaning either, each of two, it has roots in the Proto-Germanic aiwatharaz, reflecting dual choices.

182 mentions per 1 million words

Very Often

Hint: Frequency according to COCA