The idiom "to pour oil in troubled waters" means to calm a dispute.
The idiom comes from the idea that pouring oil on troubled water will help to smooth it out. In the same way, saying or doing something that is helpful or conciliatory can help to calm a disagreement or argument.
For example, you might say "I tried to pour oil on troubled waters by suggesting that we take a break from the discussion." This means that you tried to calm the situation by suggesting a way to de-escalate the argument.
The other options are not as accurate descriptions of the meaning of the idiom.
- To create tension: This idiom is more accurately described as "to stir up trouble."
- To light a fire: This idiom is more accurately described as "to start a conflict."
- To raise a controversy: This idiom is more accurately described as "to generate a lot of discussion or debate."
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