It's important to distinguish between:
* Nouns: These are words that represent people, places, things, or ideas. They are a core part of sentence structure. Examples: *dog, table, happiness, London*.
* Syntax: This refers to the rules that govern how words are combined to form grammatically correct sentences.
Therefore, the term "syntactic noun" doesn't have a clear and widely accepted meaning.
It's possible the term is being used to refer to:
* Noun phrases: These are groups of words that function as a noun. They often include a noun as their headword. Examples: *the big red dog, my favorite book, the city of Paris*.
* Nouns used in specific syntactic functions: Nouns can act as subjects, objects, complements, or other grammatical functions within a sentence.
If you encountered the term "syntactic noun" in a specific context, please provide more details about where you saw it, and I can help you understand its meaning.