English arriving with four missing jewellery (7)
I believe the answer is:
earring
'missing jewellery' is the definition.
'earring' can be an answer for 'jewellery' (type of jewellery). I'm not sure about the 'missing' bit.
'english arriving with four' is the wordplay.
'english' becomes 'E' (abbreviation as in OED).
'arriving' becomes 'arr' (abbreviation used in transport).
'with four' becomes 'ing' (I am not sure about this - if you are sure you should believe this answer much more).
'e'+'arr'+'ing'='EARRING'
Can you help me to learn more?
(Other definitions for earring that I've seen before include "Aural pendant" , "Lobe pendant" , "Piece of jewellery" , "Otic adornment" , "Decoration" .)