The most common and most likely answer to this crossword clue is the 12 letter word FLAT-EARTHER
I've seen this crossword clue in The Times
F
L
A
T
-
E
A
R
T
H
E
R
Buddy explains!
The straight part
We know that "one's out of touch" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one's out of touch = flat-earther.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 FLAT-EARTHER mean?
FLAT-EARTHER noun- A person who believes or advocates the theory that the planet Earth is flat.
- (by extension) A person who believes or advocates an outlandish, discredited theory; a person who refuses to acknowledge the truth despite overwhelming evidence.