Sentence:  Four buffalo gals go 'round the <WSD>outside</WSD> / 'Round the <WSD>outside</WSD> / 'Round the <WSD>outside</WSD> / Four buffalo gals go 'round the <WSD>outside</WSD> / And do-si-do your partners. 
Meaning of the word marked with <WSD> tags:  The space beyond some limit or boundary.