What are the examples of nouns that plural in form but singular meaning?

You're looking for nouns that are singular in meaning but plural in form, also known as singularia tantum. Here are some examples:

Common Examples:

* News: You wouldn't say "a news," but "a piece of news."

* Physics: You wouldn't say "a physics," but "a principle of physics."

* Politics: You wouldn't say "a politics," but "a political issue."

* Mathematics: You wouldn't say "a mathematics," but "a mathematical formula."

* Economics: You wouldn't say "an economics," but "an economic crisis."

* Athletics: You wouldn't say "an athletics," but "an athletic event."

Less Common Examples:

* Billiards: You wouldn't say "a billiards," but "a game of billiards."

* Mumps: You wouldn't say "a mumps," but "a case of mumps."

* Measles: You wouldn't say "a measles," but "a case of measles."

* Series: You wouldn't say "a series," but "a television series."

* Species: You wouldn't say "a species," but "a unique species."

Things to Remember:

* Not all nouns that end in "-s" are singularia tantum. Many words ending in "-s" are simply plural nouns (e.g., cats, dogs, chairs).

* The meaning of the word determines whether it's singularia tantum. Even though "politics" is a singularia tantum, "politicians" is a plural noun.

Let me know if you'd like more examples or explanations!