The most common and most likely answer to this crossword clue is the 11 letter word EVERLASTING
I've seen this crossword clue in The Daily Telegraph
E
V
E
R
L
A
S
T
I
N
G
Buddy explains!

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 EVERLASTING mean?
EVERLASTING noun- An everlasting flower.
- A durable cloth fabric for shoes, etc.
- Lasting or enduring forever; existing or continuing without end
- Continuing indefinitely, or during a long period; perpetual; sometimes used, colloquially, as a strong intensive.
- Existing with infinite temporal duration (as opposed to existence outside of time).
- Extremely.