Yasimen, I don't understand why you seem to think it's important to know what the name "Chasez" means in order to marry someone outside of the Jewish faith. If you really are Jewish, and concerned about "losing your parents' faith", then you need to speak to your Rabbi (or to your parents' Rabbi) about the matter. You didn't mention whether your family is Orthodox, Conservative, or Reform.
Honestly, Yasimen, the meaning and origin of your fiance's name in a matter such as this is of no importance. Jews have been adopting "non-Jewish" names for centuries.
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Nanaea