The most common and most likely answer to this crossword clue is the 7 letter word ABORTED
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More clues leading to the result ABORTED
Buddy explains!

The straight part
We know that "decided not to run" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case decided not to run = aborted.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 ABORTED mean?
ABORTED verb- (now rare outside medicine) To miscarry; to bring forth (non-living) offspring prematurely.
- To cause a premature termination of (a fetus); to end a pregnancy before term.
- To end prematurely; to stop in the preliminary stages; to turn back.
- To stop or fail at something in the preliminary stages.
- To become checked in normal development, so as either to remain rudimentary or shrink away wholly; to cease organic growth before maturation; to become sterile.
- To cause an organism to develop minimally; to cause rudimentary development to happen; to prevent maturation.
- To abandon a mission at any point after the beginning of the mission and prior to its completion.
- To terminate a mission involving a missile or rocket; to destroy a missile or rocket prematurely.
- To terminate a process prior to completion.
- Brought forth prematurely.
- Checked in normal development at an early stage.
- Rendered abortive or sterile; undeveloped.