The most common and most likely answer to this crossword clue is the 8 letter word ADENOIDS
I've seen this crossword clue in The Guardian
A
D
E
N
O
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D
S
More clues leading to the result ADENOIDS
- Glandular tissue helps to hide malformed node
- Tissue’s wrongly diagnosed after black part of lung is removed
- Poster girl’s getting over old breathing restriction
- Said and done resolving source of complaint
- They may cause snoring noise Dad put out
- Recollects girl one found in plugs for nasal tissue
- Glands from some south Arabian people?
Buddy explains!
The straight part
We know that "breathing restriction" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case breathing restriction = adenoids.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 ADENOIDS mean?
ADENOIDS noun- One of two folds of lymphatic tissue covered by ciliated epithelium. They are found in the roof and posterior wall of the nasopharynx at the back of the throat behind the uvula. They may obstruct normal breathing and make speech difficult when swollen, a condition often called adenitis.