The most common and most likely answer to this crossword clue is the 4 letter word NILE
I've seen this crossword clue in Financial Times
N
I
L
E
More clues leading to the result NILE
- Retired priest following northern river
- Long-distance runner having zero energy
- River's inlet almost diverted
- Flower that’s small and delicate, not strong, knocked over
- River essential for Egyptian, I learn
- Imbecile decapitated flower
- Flower, one planted by lake in Northumberland?
- North-east contains one large river
- Long-distance runner’s taken part in marathon, I learned
- Flower girl regularly seen in Tyneside
Buddy explains!
The straight part
We know that "Long-distance runner" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case long-distance runner = nile.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.