Odd occasional slight clunk

[Yaris in France]

Greetings,
I have a 2013 Yaris (hatchback) ... mileage = 18,000 miles. I've recently noticed a slight clunk (but only occasionally) under some of the following conditions:
1. Downhill (but not necessarily on uphill corners) on tight turns regardless of whether the brakes are engaged or not.
2. Turning into a parking space.

Since I will need to take it to a mechanic here and will be dealing with this in a language I don't speak well, I'd like to have a hint ahead of time as to what might be the problem.

I thought perhaps the car needed to be lubed, but I guess cars this new don't need to be lubed (?)

I should add that I live in a very windy area near the sea with heavy salt air seasonally.

thanks ...