Tugs moved by wind (4)
I believe the answer is:
gust
'wind' is the definition.
(gust of wind)
'tugs moved' is the wordplay.
'moved' indicates anagramming the letters.
'tugs' is an anagram of 'GUST'.
'by' is the link.
(Other definitions for gust that I've seen before include "Puff (of wind)" , "A big blow" , "Blast of air" , "Squall" , "Sudden blast of wind" .)