Crossword Genius

A process in calculating a high degree; it has no one returning (8)

Ross

I believe the answer is:

addition

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

'a process' is the definition.
(addition is a kind of process)

'calculating a high degree it has no one returning' is the wordplay.
'calculating a high' becomes 'ad' (I can't justify this - if you can you should give a lot more credence to this answer).
'degree' becomes 'd' (abbreviation for the degree in measuring angles).
'has' is a charade indicator (letters next to each other).
'one' becomes 'I' (Roman numeral).
'returning' says the letters should be written in reverse.
'no'+'i'='noi'
'noi' in reverse letter order is 'ion'.
'ad'+'d'+'it'+'ion'='ADDITION'

'in' is the link.

Can you help me to learn more?

(Other definitions for addition that I've seen before include "Calculation of the sum of two or more" , "Simple kind of arithmetic" , "an arithmetical process" , "'Increase, augmentation (8)'" , "Reckoning" .)

I've seen this clue in the Sydney Morning Herald.
Want a hint initially instead of a full solution? Install my app