When you don't exactly have a crush on someone, but you think they have a hot body, although you don't like their face.
You could very well be saying that you would be crushing on a butters person.
It formed from the words "crush" and "lust"
"I don't have a crush on Tom, but damn, I have a huge clust on him." Sarah said.
"Hey, are you saying I have an ugly face?" Tom replied as he overheard the conversation.