Bony langur falters after adult (7)
I believe the answer is:
angular
'bony' is the definition.
(I've seen this before)
'langur falters after adult' is the wordplay.
'falters' indicates an anagram (I've seen 'faltering' mean this).
'after' is a charade indicator (letters next to each other).
'adult' becomes 'a' (abbreviation).
'langur' anagrammed gives 'ngular'.
'ngular' put after 'a' is 'ANGULAR'.
(Other definitions for angular that I've seen before include "Having sharp lines and corners" , "Bony - lean - gaunt" , "With jagged outline" , "with geometric design" , "Having sharp edges or corners" .)