Is talkative a synonym or antonym?

"Talkative" is neither a synonym nor an antonym. It's a standalone word describing someone who enjoys talking a lot.

Here are some synonyms for "talkative":

* Chatty

* Loquacious

* Voluble

* Gabby

* Garrulous

Here are some antonyms for "talkative":

* Quiet

* Silent

* Reserved

* Shy

* Introverted