The most common and most likely answer to this crossword clue is the 10 letter word RELENTLESS
I've seen this crossword clue in Financial Times
R
E
L
E
N
T
L
E
S
S
More clues leading to the result RELENTLESS
- Persistent seller sent off
- Stubborn, will give way comparatively little
- About to join fast requiring not so much? Tharsh
- Not faltering, advanced through lesser evil
- Brutal advice to those who yield too easily
- Persistent crew in the middle, not fast?
- Unyielding regarding missing holy period?
- Soldiers advanced without being persistent
Buddy explains!
The straight part
We know that "Not faltering" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case not faltering = relentless.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 RELENTLESS mean?
RELENTLESS adjective- Unrelenting or unyielding in severity.
- Unremitting, steady and persistent.