The most common and most likely answer to this crossword clue is the 6 letter word CONVOY
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More clues leading to the result CONVOY
Buddy explains!

The straight part
We know that "escort" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case escort = convoy.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 CONVOY mean?
CONVOY noun- One or more merchant ships sailing in company to the same general destination under the protection of naval vessels.
- A group of vehicles travelling together for safety, especially one with an escort.
- The act of convoying; protection.
- To escort a group of vehicles, and provide protection.