Newspaper boss makes investment finally in English fashion house (6)
I believe the answer is:
editor
'newspaper boss' is the definition.
(I've seen this before)
'investment finally in english fashion house' is the wordplay.
'finally' suggests the final letters.
'in' indicates putting letters inside.
'english' becomes 'e' (abbreviation).
'fashion house' becomes 'dior' (I've seen this in other clues).
The last letter of 'investment' is 't'.
'e'+'dior'='edior'
't' put into 'edior' is 'EDITOR'.
'makes' is the link.
(Other definitions for editor that I've seen before include "Newspaperman" , "One is responsible for publication" , "Do tie out the newspaper head" , "Redactor" , "Do tire out the press person" .)