Days after five in a moonwalk perhaps made great strides (8)
I believe the answer is:
advanced
'made great strides' is the definition.
(to advance is to go forward)
'days after five in a moonwalk' is the wordplay.
'days' becomes 'd' (abbreviation for days).
'after' is a charade indicator (letters next to each other).
'five' becomes 'V' (Roman numeral).
'in' means one lot of letters goes inside another.
'moonwalk' becomes 'dance' (moonwalk is a type of dance).
'a'+'dance'='adance'
'v' going inside 'adance' is 'advance'.
'd' after 'advance' is 'ADVANCED'.
'perhaps' acts as a link.
(Other definitions for advanced that I've seen before include "Hi-tec truck" , "progressive" , "Sophisticated" , "Went forward, being far on" , "At a higher level" .)