Sentence:  The covers <WSD>slid</WSD> down his skinny neck so I saw his head , fuzzed like a dandelion gone to seed , but his face was turned to the wall - there was the pale shadow of his nose on the plaster - and I thought , Well you do n't look much like a pig-drunk bully now . 
Meaning of the word marked with <WSD> tags:  to pass or move unobtrusively or smoothly