What does the 망정 in 망정이지 mean?

 ANSWER: fortunate or lucky

It is not in my Korean-English dictionary, but the supposedly pure-Korean word 망정 in 망정이지 means "lucky" or "fortunate," but why does it mean "lucky" or "fortunate"? What is the origin of the word? I cannot find anything on its etymology.

The word 망정 does appear in my Korean-Korean dictionary with the following definition:

"[대개, '-니 망정이지' 또는 '-기에 망정이지'의 꼴로 쓰이어] '-니(기에) 다행이지'의 뜻을 나타내는 말."

"[Usually used in the form of '-니 망정이지' or '-기에 망정이지'], the word appears to mean 'to be fortunate/lucky with something' (니/기에 다행이지)."

So, instead of saying 망정이지, one could say 다행이지 (lucky/fortunate).

There is also an example sentence with the definition:

"미리 알았기에 망정이지 큰일날 뻔했다"

"It's lucky we knew in advance; we almost had a big problem."

Though my Korean-Korean dictionary does not say anything about the etymology of the "lucky/fortunate" 망정, it does list another 망정 (望定) just below it that is defined as follows:

"조선때 관원을 천거(薦擧)할 때 후보자로 세 사람을 지명하던 일"

"The act of nominating three candidates for a government post during the time of Joseon."

Could the "lucky/fortunate" pure-Korean 망정 be related to the "nominating three candidates for a government post" Sino-Korean 망정 (望定)?

I wonder because the Chinese characters in the Sino-Korean word 망정 (望定) literally mean "a wish or hope (望) is decided (定)," which would be "lucky" or "fortunate" for the person whose "wish or hope was decided (망정)." It could also be translated as "a hopeful or desired decision."

From "동아 새國語辭典" (1992)