Does anyone have insight into what 「元気をなくすとは」means? I am aware that 元気 is "energy" and なくす is "to lose". So "to lose energy" makes sense? However I am not altogether sure what とは means in this instance. A Japanese friend asked me for an English equivalent and I wasn't sure if this was colloquial somehow?
Thank you in advance!
“元気をなくす” means “lose energy”, “lose their health” or “being down”. You can use on physical matter and mental matter both.
Regarding meaning of “とは”:
It’s hard to say without seeing whole sentence but if that word is using like below it have implication that "you shouldn't". I think there are no words in english to replace it completely. I tried to find good example..
彼女に捨てられたくらいで元気をなくすとは情けない。
Don’t be so down just because she dumped you. How pathetic you are.
In this case, its meaning is similar to "～するなんて".
I am not altogether sure what とは means in this instance.← What instance? You have not provided any context. 「とは」 can mean a couple of completely different things and only the context will tell what meaning it is used for.