na-adjective
indiscreet; thoughtless; careless
Describes a person or action that lacks discretion, prudence, or careful consideration. Rare literary word; modern Japanese would more often use 軽率な or 不注意な.
彼の軽忽な発言が問題を大きくした。
His indiscreet remark made the problem worse.
na-adjective
Used for something so foolish or unreasonable that it invites ridicule. Rare and somewhat literary; 馬鹿げた or 滑稽な are more common in modern speech.
そんな軽忽な言い訳は誰も信じない。
Nobody will believe such an absurd excuse.
na-adjective
disdaining; belittling; scornful
Shows contempt or a dismissive attitude toward someone or something. Rare; modern equivalents include 軽蔑した or 見下した.
彼は相手を軽忽な目で見た。
He looked at the other person with a disdainful eye.
Alternate kanji form; also rare.
The exact derivation is uncertain. The kanji 軽 (light, frivolous) and 忽 (neglect, disregard) or 骨 (bone, but here likely used for its sound) suggest a meaning of treating something lightly or with contempt. The word is rare and appears mainly in older or literary contexts.