Underwear has one inside leering, unfortunately (8)
I believe the answer is:
lingerie
'underwear' is the definition.
(type of underwear)
'one inside leering unfortunately' is the wordplay.
'one' becomes 'i' (Roman numeral).
'inside' is an insertion indicator.
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'leering' anagrammed gives 'lingere'.
'i' put inside 'lingere' is 'LINGERIE'.
'has' is the link.
(Other definitions for lingerie that I've seen before include "One from W Atlantic island group" , "frillies" , "Female underwear" , "stockings, say?" , "Ladies' underwear" .)