Costly traps one second before software to expire (9)

I believe the answer is:

disappear

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'expire' is the definition.
(thesaurus)

'costly traps one second before software' is the wordplay.
'costly' becomes 'dear' (synonyms).
'traps' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'second before' becomes 's' (common abbreviation. I am not sure about the 'before' bit.).
'software' becomes 'app' (software application).
'i'+'s'+'app'='isapp'
'dear' placed around 'isapp' is 'DISAPPEAR'.

'to' is the link.

Can you help me to learn more?

(Other definitions for disappear that I've seen before include "go by the board" , "Escape" , "Leave" , "Go missing" , "exit" .)

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

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