Antonyms of adj flighty

2 senses of flighty

Sense 1
flighty, flyaway, head-in-the-clouds, scatterbrained -- (guided by whim and fancy; "flighty young girls")

INDIRECT (VIA frivolous) -> serious -- (concerned with work or important matters rather than play or trivialities; "a serious student of history"; "a serious attempt to learn to ski"; "gave me a serious look"; "a serious young man"; "are you serious or joking?"; "Don't be so serious!")

Sense 2
skittish, flighty, spooky, nervous -- (unpredictably excitable (especially of horses))

INDIRECT (VIA excitable) -> unexcitable -- (not easily excited; "an unexcitable temperament")

Similarity of adj flighty

2 senses of flighty

Sense 1
flighty, flyaway, head-in-the-clouds, scatterbrained -- (guided by whim and fancy; "flighty young girls")
       => frivolous (vs. serious) -- (not serious in content or attitude or behavior; "a frivolous novel"; "a frivolous remark"; "a frivolous young woman")

Sense 2
skittish, flighty, spooky, nervous -- (unpredictably excitable (especially of horses))
       => excitable (vs. unexcitable) -- (easily excited)