Sturdy or sadly broken (6)
I believe the answer is:
robust
'sturdy' is the definition.
(similar in meaning)
'or sadly broken' is the wordplay.
'sadly' indicates anagramming the letters.
'broken' becomes 'bust' (bust can mean broken).
'or' is an anagram of 'ro'.
'ro'+'bust'='ROBUST'
(Other definitions for robust that I've seen before include "Vigorous - healthy" , "Forceful" , "Rugged and sturdy" , "Athletic" , "Having a strong constitution" .)