The most common and most likely answer to this crossword clue is the 6 letter word GIRLIE
G
I
R
L
I
E
Buddy explains!

The straight part
We know that "sexist address" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sexist address = girlie.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GIRLIE mean?
GIRLIE noun- A magazine targeting an adult male audience and containing nude or semi-nude photographs of women.
- A young girl.
- Of entertainment, involving attractive women or images thereof, usually nude or wearing skimpy clothing.
- Characteristic of a stereotypical girl, very effeminate, sweet; unmasculine.