The most common and most likely answer to this crossword clue is the 8 letter word CORVETTE
I've seen this crossword clue in The Times
C
O
R
V
E
T
T
E
More clues leading to the result CORVETTE
- Escort vessel my inspector endlessly provides
- Warship conquistador's docked taking surgeon aboard
- Old soldier heading for trouble aboard key warship
- Check temperature in essential component of sports car
- Naval vessel runs old fighter into shelter built for fliers
- Naval vessel and similar things returned carrying soldiers
- Ship’s doctor tried initially, cutting heart
- Escort vessel – check last of ballast in centre
Buddy explains!

The straight part
We know that "Warship" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case warship = corvette.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 CORVETTE mean?
CORVETTE noun- A flush-decked warship of the 17th-18th centuries having a single tier of guns; it ranked next below a frigate; – called in the United States navy a sloop of war.
- In a modern navy, a lightly armed and armoured blue water warship, smaller than a frigate, capable of transoceanic duty.