One is glad criminal is close (9)
I believe the answer is:
alongside
'is close' is the definition.
(thesaurus)
'one is glad criminal' is the wordplay.
'criminal' indicates an anagram.
'one'+'is'+'glad'='oneisglad'
'oneisglad' is an anagram of 'ALONGSIDE'.
(Other definitions for alongside that I've seen before include "Adjacent to" , "Aligned so as to be next to, as ship moored to pier" , "Lying close to" , "Next to, another boat perhaps" , "next door" .)