The most common and most likely answer to this crossword clue is the 11 letter word FRANCOPHONE
I've seen this crossword clue in The Times
F
R
A
N
C
O
P
H
O
N
E
More clues leading to the result FRANCOPHONE
Buddy explains!

The straight part
We know that "one like de Gaulle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one like de gaulle = francophone.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 FRANCOPHONE mean?
FRANCOPHONE noun- A person who speaks French, especially as their mother tongue.
- French-speaking.