Languages once spoken and not used — only internally (5)

I believe the answer is:

norse

I'm a little stuck... Click here to teach me more about this clue!

'languages once spoken' is the definition.
I can't judge whether this defines the answer.

'and not used only internally' is the wordplay.
'and' becomes 'n' (common abbreviation for 'and').
'not used' becomes 'ors' (I can't justify this - if you can you should believe this answer much more).
'only' becomes 'amere' (I've seen this in another clue).
'internally' means to look at the middle letters.
The central letter of 'amere' is 'e'.
'n'+'ors'+'e'='NORSE'

Can you help me to learn more?

(Other definitions for norse that I've seen before include "Relating to ancient Scandinavia" , "Old Scandinavian tongue" , "Relating to ancient Scandinavian" , "like the Valkyries?" , "Family of Germanic languages spoken in Scandinavia and Iceland" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.