noun
ordinary person; average person
Refers to a person without special abilities or status; often used in contrast to experts, geniuses, or extraordinary individuals.
彼は常人とは思えないほどの集中力を持っている。
He has a level of concentration that is hard to believe for an ordinary person.
常人には理解できない発想だ。
It's an idea that an average person cannot understand.
Compound of 常 (じょう, 'usual, ordinary') and 人 (じん, 'person'). The reading じょうじん is the standard on'yomi combination.