Engineers sign code that's compiled and accepted as valid (10)
I believe the answer is:
recognised
'and accepted as valid' is the definition.
I can't tell whether this definition defines the answer.
'engineers sign code that's compiled' is the wordplay.
'engineers' becomes 're' (abbreviation for Royal Engineers).
'that's compiled' indicates anagramming the letters.
'sign'+'code'='signcode'
'signcode' with letters rearranged gives 'cognised'.
're'+'cognised'='RECOGNISED'
Can you help me to learn more?
(Other definitions for recognised that I've seen before include "given approval" , "Was aware of" , "Acknowledged" , "appreciated" .)