Call in (5)
'call in' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for visit that I've seen before include "Look up" , "Call in to see, socially or on business" , "Inflict" , "Drop in; frequent" , "Come to see" .)
(Other definitions for sick that I've seen before include "Ill; perverted" , "vomit" , "Ailing" , "Poorly" , "Bad" .)