The most common and most likely answer to this crossword clue is the 11 letter word DOUBLETHINK
I've seen this crossword clue in Financial Times
D
O
U
B
L
E
T
H
I
N
K
Buddy explains!

The straight part
We know that "Orwellian concept" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case orwellian concept = doublethink.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 DOUBLETHINK mean?
DOUBLETHINK noun- The holding of two contradictory beliefs in one's mind simultaneously and accepting both of them as true or correct, without realizing the contradiction.