A flippant and unreliable person.

figurative. A capricious, giddy, or frivolous person, esp. one having a gaudy or showy appearance.

One who dallies: see the verb.

attributive and in other combinations, as fling period (sense 5); fling-brain n. Obsolete a person of flighty and hasty character. fling-brained adj.…

(figurative) a flighty, empty-headed fellow.

An inconsiderate or thoughtless person.

figurative. Applied to a person.

a light-headed or giddy person.

A fantastical, frivolous person. Obsolete exc. dialect.

A person of ‘cracked’ brain or wandering wits; a giddy, thoughtless person.

= shatter-brain, n.

One who is incapable of serious connected thought; a thoughtless, giddy person.

a flighty or light-headed person.

a frivolous or flighty person; (literally) a will-o'-the-wisp.

a person who is ‘ditzy’, scatterbrained, or cute.