12
half ass
8
rattlepated
8
scatterbrained
5
flighty
5
harebrained
5
scatty
4
silly
3
frivolous
3
giddy
3
thoughtless
2
absent
2
absentminded
2
abstracted
2
jejune
2
mad
1
absurd
1
airheaded
1
bird brained(expression, idiom)
1
blank
1
brainless
11 years ago|3k views|share |citing 
APASmart Define. (2015). rattlebrained thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/rattlebrained/thesaurus/synonyms
ChicagoSmart Define. 2015. "rattlebrained thesaurus" https://smartdefine.org/rattlebrained/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, rattlebrained thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/rattlebrained/thesaurus/synonyms>.
MLASmart Define. "rattlebrained thesaurus" 10 April 2015. Web. 21 September 2026. <https://smartdefine.org/rattlebrained/thesaurus/synonyms>