The most common and most likely answer to this crossword clue is the 6 letter word IMPOST
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P
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T
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The straight part
We know that "/Exact" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case /exact = impost.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 IMPOST mean?
IMPOST noun- A tax, tariff or duty that is imposed, especially on merchandise.
- The weight that must be carried by a horse in a race, the handicap.
- The top part of a column, pillar, pier, wall, etc. that supports an arch.