By way of taking a girl to central Spain (3)
I believe the answer is:
via
'by way of' is the definition.
(via means by way of or by means of)
'a girl to central spain' is the wordplay.
'a girl' becomes 'Vi' (short for Violet).
'to central' indicates the central letters.
The middle letter of 'spain' is 'a'.
'vi'+'a'='VIA'
'taking' is the link.
(Other definitions for via that I've seen before include "Going through" , "Passing through" , "By way of - in Latin" , "A Roman way" , "Roman road" .)