Ready to move, covering a good distance (7)
I believe the answer is:
yardage
'distance' is the definition.
(distance measured in yards)
'ready to move covering a good' is the wordplay.
'to move' indicates an anagram.
'covering' indicates putting letters inside.
'good' becomes 'g' (abbreviation).
'ready' is an anagram of 'yarde'.
'a'+'g'='ag'
'yarde' placed around 'ag' is 'YARDAGE'.
(Other definitions for yardage that I've seen before include "charge for using court" , "Amount of fabric" , "particular distance" , "What a caddy should know" , "use of enclosed space" .)