I. ˈrə-nə-ˌwā noun
Date: 1547
1. : one that runs away from danger, duty, or restraint : fugitive
2. : the act of running away out of control ; also : something (as a horse) that is running out of control
3. : a one-sided or overwhelming victory
II. adjective
Date: 1548
1.
a. : running away : fugitive
b. : leaving to gain special advantages (as lower wages) or avoid disadvantages (as governmental or union restrictions)
runaway shipping firms
a runaway shop
2. : accomplished by elopement or during flight
3. : won by or having a long lead
a runaway success
also : extremely successful
a runaway best seller
4. : subject to uncontrolled changes
runaway inflation
5. : being or operating out of control
a runaway oil well
a runaway nuclear reactor