Synonyms are words which have almost the same meaning for the given context. They are not exact equivalents.
Since some words can have multiple meanings, one must be careful of the meaning associated with a synonym.
The synonyms of Lexicon include
Their usage depends on the context.
In general, Lexicon is a body of knowledge (or dictionary) of Latin and Greek.
At one time, Lexicon is a card game where players create words and score points. It was superseded by Scrabble.