brand new

adjective2

1. •
   Utterly new, as new as possible.

   • It's a rough trip no matter how you come, for these washboard roads will loosen up even brandnew cars pretty fast; and hitchhikers always find the going bad. — 1948
2. •
   (slang) Acting in a way unusual for oneself.

   • Man, quit actin' brand new, bruh. You only being this way 'cause there's a girl.