Tell engineers get overdue (6)
I believe the answer is:
relate
'tell' is the definition.
(as in to tell or relate a story)
'engineers get overdue' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'get' says to put letters next to each other.
'overdue' becomes 'late' (similar in meaning).
're'+'late'='RELATE'
(Other definitions for relate that I've seen before include "Do well; wave about" , "how to get on?" , "link" , "Narrate, tell in detail" , "Narrate in Tralee" .)