Flipped lid with one fellow who's industrious (8)
I believe the answer is:
diligent
'industrious' is the definition.
(similar in meaning)
'flipped lid with one fellow' is the wordplay.
'flipped' shows that the letters should be reversed in order.
'with' says to put letters next to each other.
'one' becomes 'i' (Roman numeral).
'fellow' becomes 'gent' (synonyms).
'lid' reversed gives 'dil'.
'dil'+'i'+'gent'='DILIGENT'
'who's' acts as a link.
(Other definitions for diligent that I've seen before include "Working hard and conscientiously" , "Taking trouble" , "Industrious" , "Assiduous" , "Steady in application and industry" .)