Yiddish meaning??

Huh - I'm mainly bumping your topic but I suppose I would ask them - because naches is kind of good things, good fortune, and it's not mazel which is luck. Is it possible they are mispronouncing a word? Were they brought up speaking Yiddish, or just a few words here and there, if you know?

Maybe a local variant of Mechayeh (great delight, joy)?

I bet you're onto something there.