How would you pronounce the word “Lucerne” ?

Loo-surn (as in burn) - best I can offer.

Lucerne is a Swiss town located on the shores of the lake of the same name.  The native language is Swiss-German.

https://en.wikipedia.org/wiki/Lucerne

Why is this question on Baby Names?

I would pronounce Lucerne as Loo suhn. A Lucerne was the Felix Rufus, the wild Bobcat of Europe. And the great basrelief the Lion of Lucerne commemorates the Swiss Guard whom the tragically foolish Louis XVI ordered to lay down their arms. 

I'd guess that's the way the Italian Swiss would pronounce the name of the lake and the town. But the Safeway brand is definitely loo-SERN. 

'Loo-sern' is the nearest in normal English pronunciation. Lucerne is the name of a lake in the French-speaking part of Switzerland, therefore its sound follows the French pattern.

To get the true French sound you need to get it face-to-face from a good speaker of French, but it is not far from Loo-sern.

Lucerne is a store brand name for Safeway and Vons.   That is their brand.   It sounds like Lou sir in.

It's Loo-sern.  I like your way better.

It's "loo-SERN." It's also a brand of dairy products.

It is pronounced “loo•sern”.  If i hadn’t seen a commercial for it i would still be calling it “loo•kern”

Yes, it is “loo-sern”.

If it had an accent ague over the e, it would be “Loo-ser-nay”

Yes, it's pronounced 'loo-sern'.