Ring up; come by (4)
I believe the answer is:
call
This clue is a double definition.
'ring up' is the first definition.
(I've seen this in another clue)
'come by' is the second definition.
(thesaurus)
(Other definitions for call that I've seen before include "Visit; shout" , "Ring or visit" , "Ireland's ..., rugby anthem" , "Phone; cry" , "Short visit" .)