The most common and most likely answer to this crossword clue is the 5 plus 2 letter word OPENS UP
I've seen this crossword clue in The Daily Telegraph
O
P
E
N
S
U
P
More clues leading to the result OPENS UP
- Reveals that one is being less reserved
- Old writer having drink becomes more communicative
- Nothing to drink after writer talks without inhibitions
- Discloses writers brought in by university press
- Author involved in creating opus speaks freely
- Oxford publisher, having gathered writers, speaks frankly
- After engaging writers, publisher says what it thinks
Buddy explains!

The straight part
We know that "talks without inhibitions" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case talks without inhibitions = opens up.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.