The most common and most likely answer to this crossword clue is the 8 letter word ADVANCED
I've seen this crossword clue in The Guardian
A
D
V
A
N
C
E
D
More clues leading to the result ADVANCED
Buddy explains!

The straight part
We know that "Lent/Lent/brought forward/brought forward" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lent/lent/brought forward/brought forward = advanced.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 ADVANCED mean?
ADVANCED verb- To promote or advantage.
- To move forward in space or time.
- To raise, be raised.
- At or close to the state of the art.
- Enhanced.
- Having moved forward in time or space (e.g. advanced ignition timing).
- In a late stage of development; greatly developed beyond an initial stage.
- Pronounced farther to the front of the vocal tract.
- (Philippine English) (Of a clock or watch) Indicating a time ahead of the correct time.