qīng​shuài

rash

轻率 (輕率) qīng​shuài
rash adjective
acting or done without careful consideration of the consequences

It is unwise to make such a rash decision.

cavalier adjective
showing a lack of proper concern or seriousness; dismissive

His flippant attitude made everyone very unhappy.

Frequency

Movie subtitles
2.41 per million appears in 1% of films
Written text
1.29 per million

Sources

Definitions
CC-CEDICT