Note engineers have direction to make beer (4)
I believe the answer is:
brew
'make beer' is the definition.
(I've seen this before)
'note engineers have direction' is the wordplay.
'note' becomes 'b' (musical note**).
'engineers' becomes 're' (Royal Engineers).
'have' means one lot of letters go next to another.
'direction' becomes 'w' (W is an example).
'b'+'re'+'w'='BREW'
'to' acts as a link.
(Other definitions for brew that I've seen before include "Prepare (drink of tea)" , "Make beer; drink of tea" , "Make, eg, beer" , "Make (tea/coffee)" , "Infusion" .)