Appear for engineers, now (9)
I believe the answer is:
represent
'appear for' is the definition.
(thesaurus)
'engineers now' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'now' becomes 'present' (the present time).
're'+'present'='REPRESENT'
(Other definitions for represent that I've seen before include "Ambassadors do it" , "Portray" , "Explain" , "Mean" , "Stand for or symbolise" .)