A dictionary has pana : adj. keeping, observing, which are unusual adjectives in English. ("the observing man?")
Nagara pana may mean *the observing city/ nation. Probably, nagara pana has another meaning. Is this a normal Skr term?
I do see that Monier-Williams gives these meanings for "pāna-", but he, unfortunately, does not provide textual references, except for a couple of compounds, where the "pāna-" element seems to rather mean "protecting". I personally found the "keeping, observing"-definition strange. So, I checked in another dictionary (Apte), which does not list this definition. Apte is a less comprehensive dictionary than MW, so this absence is not a "death-blow", but it probably suggests that it is not a common meaning.
In my opinion, the meaning "protecting" for "pāna-" as the second element of a compound is more plausible than "observing, keeping" (but, there exists a semantic overlap between them anyway), yielding (theoretically) "nagara-pāna-", either one who protects the city, or protection of the city (the second sounds more normal). I could not, however, find any evidence that this term had ever been used in Sanskrit.
It should also be noted that "pāna-" also has an unrelated and probably more common meaning - "drinking". There exists another word with different pronunciation - "paṇa-", meaning wager/bet/stake in gambling, etc. Using that word, "nagara-paṇa-" could conceivably mean "(a bet, etc.) with a city as the wager", etc. but that takes us far away from what you were looking for...
Btw. for clearer and more pointed answer, you need to provide more context, e.g. where you came across this term, preferably exact sentence, etc.
Thanks, an online dict. gives about 13 adjectives "nagara" and about 13 nouns. Maybe the term is nagara (adj) and paNa (noun)? business. treaty.
The isolated expression is an Australian Aboriginal vocabulary meaning "initiation ceremony". A common concept is tribal rights of "men's business . women's business". There are numerous Balinese Hindu apparent cognates in Oz and about 300 Indonesian loanwords, being about 50% Skr. The land of Bali as a Hindu state was a Negara (= Malay nagara) and Balinese Pura Panataran is temple. state. head, of nagara adat nation customs, for making treaties with internal ritual chieftains.On that basis, nagara pana is nation State. Not bad for just an initiation ritual........
It is entirely possible that some Australian languages, and in particular those spoken in Northern Australia, have borrowed vocabulary from Austronesian languages (e.g. Malay or Javanese), including Sanskrit or Arabic loanwords in Austronesian. But in this particular case, the fact that *nagara-pāna- does not seem to occur in Sanskrit or in any Austronesian language does not favour such a derivation. Besides, the semantic connection between “protector of the city” and “initiation” is anything other than obvious.
I would imagine that nagara wat > Angkor Wat is not an Indian expression? The Javanese idiom Negurah Mpu ruling priest appears to be a novelty, and may be ngurrampaa tribal camp-place, (seat of elders' council ), in the same region as ngara pana. Initiation produced tribal men with skin-scars and knowledge of tribal doctrines. Their Ringbalin follow the warrior ceremony along the Barka Indji (bhaga induji?) corresponds to Skt / Balinese ring balin.
A camp-place as the Aust. equivalent of a city seems plausible, in the context of Nguralla north-west West Australia area, also a council for implementing government treaties, local committee meaning at home to promote employment and also a lore camp.