Went over, but outmoded in irrational number (9)
I believe the answer is:
surpassed
'went over' is the definition.
The answer and definition can be both related to competing as well as being past participle verbs.
Maybe there's a link between them I don't understand?
'outmoded in irrational number' is the wordplay.
'outmoded' becomes 'passe' (synonyms).
'in' is an insertion indicator.
'irrational number' becomes 'surd' (I've seen this in another clue).
'passe' put into 'surd' is 'SURPASSED'.
'but' is the link.
Can you help me to learn more?
(Other definitions for surpassed that I've seen before include "beaten" , "Outdid" , "outclassed" , "capped" .)