The most common and most likely answer to this crossword clue is the 6 letter word BLEEDS
I've seen this crossword clue in The Daily Telegraph
B
L
E
E
D
S
Buddy explains!
The straight part
We know that "Runs" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case runs = bleeds.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 BLEEDS mean?
BLEEDS noun- An incident of bleeding, as in haemophilia.
- A narrow edge around a page layout, to be printed but cut off afterwards (added to allow for slight misalignment, especially with pictures that should run to the edge of the finished sheet).
- (sound recording) The situation where sound is picked up by a microphone from a source other than that which is intended.
- The removal of air bubbles from a pipe containing other fluids.
- (of a person or animal) To lose blood through an injured blood vessel.
- To let or draw blood from.
- To take large amounts of money from.
- To steadily lose (something vital).
- (of an ink or dye) To spread from the intended location and stain the surrounding cloth or paper.
- To remove air bubbles from a pipe containing other fluids.
- To bleed on; to make bloody.
- To show one's group loyalty by showing (its associated color) in one's blood.
- To lose sap, gum, or juice.
- To issue forth, or drop, like blood from an incision.
- (of a phonological rule) To destroy the environment where another phonological rule would have applied.