It's Merriam-Webster's Word of the Day for July 19th.
Today's word is non-plus, spelled as one word, N-O-N-P-L-U-S.
Non-plus is a verb.
To non-plus someone is to perplex them, or in other words,
to cause them to be at a loss as to what to say, think, or do.
Here's the word used in a sentence from the Atlantic.
Motherhood is only somewhat less likely to non-plus the reader than how should a person be.
On one level, it's a feminist disputation over art versus maternity,
whether a female writer must be a mother or whether she can get away with being just,
just, a writer.
But this is also a book about life with a capital L. Does the word non-plus perplex you?
You aren't alone.
Some people believe the non in non-plus means not,
and assume that to be non-plus is to become and poised.
But in fact, the opposite is true.
If you are among the baffled, the words history may clarify things.
In Latin, non-plus means no more.
When non-plus debuted in English in the 16th century,
it was used as a noun synonymous with the word quandary.
Someone brought to a non-plus had reached an impasse in an argument and could say no more.