To stop or hold back something (often something bad) from progressing or spreading; to check or stem.
消防隊のおかげで火事の拡大を食い止めることができた。
Thanks to the firefighters, they were able to stop the fire from spreading.
感染拡大を食い止めるために外出を控えてください。
Please refrain from going out to help stop the spread of the infection.
彼は債務の増加を食い止めようと生活費を切り詰めた。
He tightened his living expenses to try to halt the increase in debt.