1. What does it mean?
냥집사 combines 냥, a cat-associated sound or shortening, with 집사, butler. It affectionately portrays a cat's human as the attendant who provides food, play, and care.
Also written or said as 고양이집사, nyangjipsa
2. The nuance
It is not a professional pet-sitting title or a claim that the cat is literally an employer. People often use it as a warm self-description.
3. Examples
“냥집사라 휴대폰에 고양이 사진이 가득해.”
As a cat parent, I have a phone full of cat photos.
“새 장난감을 고르는 건 냥집사의 즐거움이야.”
Choosing a new toy is one of the joys of being a cat's butler.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.