The most common and most likely answer to this crossword clue is the 6 letter word EXOCET
I've seen this crossword clue in The Times
E
X
O
C
E
T
More clues leading to the result EXOCET
- Missile briefly guided northwards, and across France
- Dead old detective backed missile
- Weapon carried around by Private Cox, evidently
- Pilot in rear of boat redirected low-level missile
- Executive officer ready to report on missile
- Missile sees helmsman in river shortly reversing
- Missile former commander gets after shelling
- Source of major charge old, old detective recalled
- This diver could get excited over
- Old books featuring church weapon
Buddy explains!

The straight part
We know that "missile" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case missile = exocet.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.