이질감이 · 이질감을
sense of difference, feeling of foreignness
Example
외국에서 오래 살다 와서 한국 문화에 이질감을 느꼈어요.
After living abroad for a long time, I felt Korean culture was foreign to me.
Word parts
이 different+질 quality+감 feeling
Literally 'feeling that the quality is different'.