scatty

adjective

1
lost in thought; showing preoccupation
an absent stare
an absentminded professor
2
lacking sense or discretion
his rattlebrained crackpot ideas
how rattlepated I am! I've forgotten what I came for"- Glenway Westcott

Also useful for “scatty”:Unscrambler— Rearrange the letters in “scatty”