1. To twist and undulate the body to propel the body forward. The snake slithered along on the hot sand, searching for bit of shade. We'll have to slither along on our bellies in order to avoid the tripwire surrounding the fortress.

2. To walk onward in a sliding motion, especially in a manner that makes others feel uneasy or distrustful. I ignored the sleazebag at the bar until he eventually slithered along to the next woman who caught his eye.