One wears this, also shabby, repulsive pants? (9)
I believe the answer is:
halitosis
'repulsive pants?' is the definition.
(as in panting - bad breath)
'one wears this also shabby' is the wordplay.
'one' becomes 'I' (Roman numeral).
'wears' means one lot of letters goes inside another.
'shabby' is an anagram indicator.
'this'+'also'='thisalso'
'thisalso' with letters rearranged gives 'halitoss'.
'i' inserted into 'halitoss' is 'HALITOSIS'.
(Other definitions for halitosis that I've seen before include "Bad breath, smells unpleasant" , "Smelly breath" , "offensive condition" , "Foul breath problem" , "repulsive pants?" .)