Synonyms of scatterbrained

1 Syllable
dull
2 Syllables
ditsy, scatty, silly, duller, dingdong, skittish, dizzy, thoughtless, stupid, swimmy, flighty, giddy, dullest, flightier, madcap, flightiest
3 Syllables
frivolous, light-minded, birdbrained, nonserious, airbrained, forgetful, lightheaded, slaphappy, careless, unwatchful, airheaded, inconscient
4 Syllables
woolgathering, illogical, irrational, empty-headed, featherbrained, addleheaded, agitable, alarmable, harebrained, rattlebrained, uncareful, undiscerning, unobserving, unperceiving, addlepated, absent-minded, addlebrained
5 Syllables
irresponsible, inattentive, unbelievable