A reader commenting on my post about pair poses this question about the nouns scissors and pants:
Isn’t each blade one scissor, and each leg part one pant?
Short answer: No.
Just because a noun ends in s does not mean there’s a matching “singular” without an s. For example, we never speak of: one athletic, one binocular, one new, one billiard, or one diabete.
Scissors has been in the language since Chaucer’s time with the meaning “a cutting instrument consisting of a pair of handled blades, so pivoted that the instrument can be opened to a shape resembling that of the letter X, and the handles then brought together again so as to cause the edges of the blades to close on the object to be cut.
The noun scissors takes a plural verb: “These scissors need to be sharpened.” Qualified by a numeral or an indefinite article, the construction “a pair of scissors” is used. The OED does show “a scissors,” but notes that it is rare. Merriam-Webster acknowledges “a scissors” with a quotation from Croswell Bowen: “took a scissors, cut the bedspread, a table scarf, and a plant.”
In my part of the U.S., one might hear any of the following:
Hand me the scissors, please.
Do you have a scissors I can use?
They gave her scissors for her birthday.
One of the blades would be called not “a scissor,” but “a scissors blade.”
For a discussion of pant vs pants, check out One Pant, Two Pants.
Some nouns that end in s are singular in meaning and take singular verbs:
Measles is still a dangerous disease.
Some say that athletics is overemphasized in American education.
Politics is the art of looking for trouble.
Mathematics is a basic school subject.
This news is not fit to print.
Billards is my favorite pastime.
Acoustics is his specialty.
Shingles is caused by the same virus as chicken pox.
Some nouns that end in s are singular in meaning and take plural verbs:
The kitten’s antics are amusing.
His earnings have remained static for five years.
These binoculars are expensive.