Wind speed (6)
I believe the answer is:
breeze
I believe this is a double definition.
'wind' is the first definition.
(breeze is a kind of wind)
'speed' is the second definition.
(thesaurus)
(Other definitions for breeze that I've seen before include "Slight wind" , "Light cooling wind" , "block-maker" , "Minor blow" , "The building block is light" .)