Engineers wanting stock control (8)
I believe the answer is:
restrain
'control' is the definition.
(restraining is a kind of controlling)
'engineers wanting stock' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'wanting' is a charade indicator (letters next to each other).
'stock' becomes 'strain' ('strain' can be a synonym of 'stock'**).
're'+'strain'='RESTRAIN'
(Other definitions for restrain that I've seen before include "In arrest (anagram)" , "Tie up - arrest" , "Stop" , "Keep in check" , "bottle up" .)