The most common and most likely answer to this crossword clue is the 7 letter word PROTECT
I've seen this crossword clue in Financial Times
P
R
O
T
E
C
T
More clues leading to the result PROTECT
- Secure red cap in container etc, screwed up
- Expert PI has time for guard
- Defend time for judge in work
- Defend positive method of learning at court
- Take care of deterioration in muscle temperature
- Strengthen rum, port, etc
- Guard heading for trouble trailing expert sleuth
- Shield Harry Potter caught inside
- Cover for the Times entertaining the City
Buddy explains!

The straight part
We know that "Secure" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case secure = protect.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 PROTECT mean?
PROTECT verb- To keep safe; to defend; to guard; to prevent harm coming to.
- (travel) To book a passenger on a later flight if there is a chance they will not be able to board their earlier reserved flight.