Engineer orders enamel primarily for decorative screen (7)
I believe the answer is:
reredos
'decorative screen' is the definition.
'reredos' can be an answer for 'screen' (a reredos is an ornamental screen). I am unsure of the 'decorative' bit.
'engineer orders enamel primarily' is the wordplay.
'engineer' is an anagram indicator.
'primarily' indicates taking the first letters.
The initial letter of 'enamel' is 'e'.
'orders'+'e'='orderse'
'orderse' with letters rearranged gives 'REREDOS'.
'for' is the link.
Can you help me to learn more?
(Other definitions for reredos that I've seen before include "Fireback" , "Red rose could show a screen behind the altar" , "Painted screen behind an altar" , "Church feature" , "Hanging in church" .)