French very upset following popular addition to magazine? (6)
I believe the answer is:
insert
'addition to magazine?' is the definition.
I can't judge whether this defines the answer.
'french very upset following popular' is the wordplay.
'french very' becomes 'tres' ('very' in French).
'upset' is a reversal indicator.
'following' means one lot of letters go next to another.
'popular' becomes 'in' ('in' can mean trendy).
'tres' back-to-front is 'sert'.
'sert' after 'in' is 'INSERT'.
Can you help me to learn more?
(Other definitions for insert that I've seen before include "Introduce, put in" , "Add in" , "Put thing in between others" , "Place within, pages of a publication say" , "Place in between other things" .)