What's the difference between thalia and thalian?

Thalia

Definition:

• (n.) That one of the nine Muses who presided over comedy.
• (n.) One of the three Graces.
• (n.) One of the Nereids.

Example Sentences:

• (1) They even got inspired: Thalia (@tatnat123) I voted because of Lil Jon.

Thalian

Definition:

• (a.) Of or pertaining to Thalia; hence, of or pertaining to comedy; comic.

Example Sentences:

• (1) Reynolds was recognised for her decades-long commitment to various charities, including the mental health organisation she founded, the Thalians.