expression, noun-modifying (irregular)
with no regard to appearances; not caring how one looks
Describes acting without concern for outward appearance or what others think; often implies desperation or single-minded focus.
彼はなりふり構わぬ格好で面接に行った。
He went to the interview with no regard to his appearance.
なりふり構わぬ努力で、彼はついに成功した。
Through desperate, all-out effort, he finally succeeded.
From なりふり (appearance, from 形振り) + 構わぬ (old negative of 構う 'to care about'). The exact historical derivation is uncertain, but the phrase is conventionally associated with disregarding one's appearance.