Organ -- one breathing? (5)

I believe the answer is:

liver

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

'organ' is the definition.
(liver is a kind of organ)

'one breathing?' is the wordplay.
'one' becomes 'li' (I've seen this in other clues).
'breathing?' becomes 'ver' (I can't justify this - if you can you should believe this answer much more).
'li'+'ver'='LIVER'

Can you help me to learn more?

(Other definitions for liver that I've seen before include "Bile-secreting organ" , "Organ; reddish-brown" , "Hepatic organ" , "Human organ" , "Viler (anag.)" .)

I've seen this clue in The Telegraph.

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.