Amorous old criminal's rank (10)
I believe the answer is:
malodorous
'rank' is the definition.
(similar in meaning)
'amorous old criminal's' is the wordplay.
'criminal's' indicates anagramming the letters (I've seen 'criminal' mean this).
'amorous'+'old'='amorousold'
'amorousold' anagrammed gives 'MALODOROUS'.
(Other definitions for malodorous that I've seen before include "Foul-smelling" , "Having a bad smell" , "Smelling very unpleasant" .)