suffix
uncharacteristic of; unbefitting; unworthy of
Attaches to nouns to express that something is not typical of or not suitable for that person or thing. Often used in negative evaluations.
See also: らしい
彼のらしからぬ発言に驚いた。
I was surprised by his uncharacteristic remark.
それはプロらしからぬミスだ。
That's a mistake unworthy of a professional.