The most common and most likely answer to this crossword clue is the 13 letter word INTERNATIONAL
I've seen this crossword clue in The Daily Telegraph
I
N
T
E
R
N
A
T
I
O
N
A
L
More clues leading to the result INTERNATIONAL
- I directed online rant at footballer?
- Put behind bars at Los Angeles, premier written up worldwide
- Left anthem unfinished in test
- Tarantino line rewritten for test, perhaps
- Big game put behind bars a short time, a lion getting agitated
- Italian tenor excited about new player for his country
- Perhaps surgeon in Scottish island left cap
- ...general latrine dirty with people inside
Buddy explains!

The straight part
We know that "test, perhaps" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case test, perhaps = international.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 INTERNATIONAL mean?
INTERNATIONAL noun- Someone who has represented their country in a particular sport.
- A game or contest between two or more nations.
- A transnational organization of political parties of similar ideology.
- Of or having to do with more than one nation.
- Between or among nations
- Participated in by two or more nations
- Common to, or affecting, two or more nations.
- Serving two or more nations
- Of or concerning the association called the International.
- Independent of national boundaries; common to all people.
- Foreign; of another nation.