Here are some words that are *close* to being homonyms for "run away", but they have slightly different meanings:
* Runaway: This is the adjective form of "run away". It describes something that has escaped or is out of control.
* Run-away: This is a hyphenated version, often used in phrases like "run-away success" or "run-away leader."
Ultimately, the best way to convey the meaning of "run away" is to simply use those words.