Cambridge dictionaries use various labels and codes, among them are:
[C] Countable noun: a noun that has a plural.
[U] Uncountable or singular noun: a noun that has no plural.
[S] A singular noun.
I do not understand the difference between a singular noun and the singular form of a countable noun. For example, with the entry "word"
sense 1:
noun [C]
a single unit of language which has meaning and can be spoken or written
sense n:
noun [S]
a brief discussion or statement:
The manager wants a word.
What if the manager wants to have several discussions? Is it impossible for us to say "The manager wants some words." because "word" here is singular?
I am confused.
Best Answer
As Færd mentioned in their comment, word in that specific meaning (the manager wants a word) cannot be used in a plural form.
Actually, having words with someone means you are having a fight with them. In that sense, words is not used in the singular.
You picked a word that has many meanings, and that is used in a lot of idiomatic expressions. Those idiomatic expressions can look very similar but still convey a vastly different meaning.