難問: difficult problem / 南門: south gate

これは何ですか: what is this?

阿南: Anan, Tokushima

come again? what did you say again? (asking the listener to repeat what was said) / what!? (expressing disbelief and shock)

Used with uncertain information. / no matter the circumstances

Used other than figuratively or idiomatically: see なん, でも.

(more informal) Alternative form of なのだ (na no da)

Used in reproach. / Used in relief.

常助: a male given name

恒美, 雅美: a male given name