'feather-brained' definitions:

Definition of 'feather-brained'

From: GCIDE

featherbrained \feath"er*brained\, feather-brained \feath"er-brained\, a. Giddy; frivolous; lacking seriousness; given to frivolity; feather-headed. [Colloq.]
Syn: airheaded, dizzy, empty-headed, giddy, lightheaded, light-headed, silly. [1913 Webster + WordNet 1.5]