To feign friendliness or innocence; to pretend to be meek or nice while hiding one's true nature (idiomatic).
彼女は初対面の人の前では猫をかぶるけど、友達にはよくくだけた話をする。
She pretends to be meek in front of people she meets for the first time, but she speaks casually with friends.
面接では猫をかぶらず、自分の強みを正直に話した方がいい。
In interviews, it's better not to pretend—honestly talk about your strengths.
職場では猫をかぶっている先輩が、実は厳格だと知って驚いた。
I was surprised to learn that the senior who acts meek at work is actually strict.