Could this mountain be the most eternal? (7)

I believe the answer is:

everest

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

'could this mountain be the most eternal?' is the definition.
'everest' can be an answer for 'mountain' (I've seen this before). I'm not certain of the remainder of the definition.

'could this mountain be the most' is the wordplay.
'could this mountain' becomes 'ever' (I can't justify this - if you can you should give a lot more credence to this answer).
'be' becomes 'rest' (resting is a kind of being).
'the most' means to remove the first letter.
'rest' with its initial letter removed is 'est'.
'ever'+'est'='EVEREST'

Can you help me to learn more?

(Other definitions for everest that I've seen before include "Highest Himalayan mountain" , "The world's highest mountain" , "Mount, climbed 1953" , "Where Hillary was" , "Huge achievement - highest climb" .)

I've seen this clue in the Sydney Morning Herald.

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.