The most common and most likely answer to this crossword clue is the 12 letter word CUTTING-EDGE
I've seen this crossword clue in Financial Times
C
U
T
T
I
N
G
-
E
D
G
E
Buddy explains!
The straight part
We know that "Modern/blade" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case modern/blade = cutting-edge.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 CUTTING-EDGE mean?
CUTTING-EDGE adjective- Representing the forefront, or position of greatest advancement in some field.