Blase (adjective)

1. Showing a lack of interest or enthusiasm, especially because of frequent exposure or indulgence.
2. Unimpressed by something because one has seen or heard it many times before.

Origin:

The word blase is derived from the french word "blasé" which means "jaded" or "bored by overfamiliarity". the word was first recorded in english in the early 19th century.

Examples:

1. He was so blase about the whole thing, it was as if nothing could surprise him anymore.
2. She was blase about the new restaurant, having tried all the others in town.
3. He was blase about the concert, having seen the band several times before.
4. She was blase about the whole situation, not showing any emotion.
5. He was blase about the news, having heard it so many times before.