Make economies, and ditch engineers first (8)
I believe the answer is:
retrench
'make economies' is the definition.
(I've seen this before)
'ditch engineers first' is the wordplay.
'ditch' becomes 'trench' (trench is a kind of ditch**).
'engineers' becomes 're' (Royal Engineers).
'first' means one lot of letters go next to another.
'trench' after 're' is 'RETRENCH'.
'and' acts as a link.
(Other definitions for retrench that I've seen before include "Cut back (on costs)" , "Cut down expenditure" , "Cut back, tighten one's belt" , "Conserve or cut down" , "Trim back" .)