Deal with engineers trapped in rubbish (5)
I believe the answer is:
treat
'deal with' is the definition.
('treat' can be a synonym of 'deal with')
'engineers trapped in rubbish' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'trapped in' means one lot of letters goes inside another.
'rubbish' becomes 'tat' (I've seen this before).
're' put inside 'tat' is 'TREAT'.
(Other definitions for treat that I've seen before include "could be a feast" , "Enjoyable surprise gift" , "Practise medicine" , "Try to heal" , "Celebration" .)