If you watch the Yuru Camp anime, I assume you've noticed this. The title of Yuru Camp in Nihongo is ゆるキャン (yuru kyan) and not ゆるキャンプ (yuru kyanpu). Can you explain to me why キャン is used instead of キャンプ which is the literal translation of camp?
I imagine that it’s just another instance of word contraction, which is common in Japanese. Here is a relevant article. In addition to everyday words, it happens often with TV shows, band names, etc.