The most common and most likely answer to this crossword clue is the 12 letter word INTELLIGENCE
I've seen this crossword clue in The Times
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More clues leading to the result INTELLIGENCE
- You might say I wait in line for some measure of this
- Ability to reason at the heart of MI6
- Military wit?
- News the teacher would welcome in any form?
- In conclusion to meeting, clientele appearing stupid — this lacking?
- Mind dope
- Hip, say, niece damaged restricts golf sharpness
- Low-down clientele getting drunk with gin
- What’s lacking in an idiot or dope
- Changing line electing wit
Buddy explains!

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 INTELLIGENCE mean?
INTELLIGENCE noun- Capacity of mind, especially to understand principles, truths, facts or meanings, acquire knowledge, and apply it to practice; the ability to comprehend and learn.
- An entity that has such capacities.
- Information, usually secret, about the enemy or about hostile activities.
- A political or military department, agency or unit designed to gather information, usually secret, about the enemy or about hostile activities.
- Acquaintance; intercourse; familiarity.