Woman visiting South American country with Mike every year (3,5)
I believe the answer is:
per annum
'every year' is the definition.
(I've seen this in another clue)
'woman visiting south american country with mike' is the wordplay.
'woman' becomes 'ann' (woman's name).
'visiting' indicates putting letters inside.
'south american country' becomes 'peru' (country in South America).
'with' means one lot of letters go next to another.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'ann' put within 'peru' is 'perannu'.
'perannu'+'m'='PER ANNUM'
(Other definitions for per annum that I've seen before include "Yearly" , "For each year - in Latin" .)