Engineers at home making check (4)
I believe the answer is:
rein
'check' is the definition.
(both can mean to control or limit)
'engineers at home' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'at home' becomes 'in' ('in' can be similar in meaning to 'at home').
're'+'in'='REIN'
'making' acts as a link.
(Other definitions for rein that I've seen before include "one's attached to a bit" , "Strap to control horse" , "kidney?" , "Check; control" , "Restraining lead" .)