The most common and most likely answer to this crossword clue is the 8 letter word UNLADING
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The straight part
We know that "take-off" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case take-off = unlading.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 UNLADING mean?
UNLADING verb- To unload.
- To disburden; take the burden from; relieve.
- To discharge the cargo from.
- To discharge a cargo; discharge a burden.
- The removal of cargo from a vessel.