The most common and most likely answer to this crossword clue is the 7 plus 7 letter word PRESENT PERFECT
I've seen this crossword clue in The Times
P
R
E
S
E
N
T
P
E
R
F
E
C
T
More clues leading to the result PRESENT PERFECT
- Hand over textbook I have left in this?
- Finding gift that’s absolutely right makes one tense
- Ideal gift given before he’s apologised or she’s reconsidered, say
- Tense? Things will never get better!
- After show, model is tense
- Tense show, faultless
- Tense and terse response to a well-chosen gift?
- Tense and concise statement of Pollyanna’s views?
Buddy explains!
The straight part
We know that "I have left in this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case i have left in this = present perfect.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.