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

The straight part
We know that "Glaring" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case glaring = conspicuous.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 CONSPICUOUS mean?
CONSPICUOUS adjective- Obvious or easy to notice.
- Noticeable or attracting attention, especially if unattractive.