Mate runs into addict (6)
I believe the answer is:
friend
'mate' is the definition.
(thesaurus)
'runs into addict' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'into' indicates putting letters inside.
'addict' becomes 'fiend' (I've seen this before).
'r' put into 'fiend' is 'FRIEND'.
(Other definitions for friend that I've seen before include "China" , "Companion; Quaker" , "Comrade for finder" , "One who gives proof of genuine regard" , "Close or intimate acquaintance" .)