Otherwise arrange a second shipment (7)
I believe the answer is:
reorder
'otherwise arrange a second shipment' is the definition.
I can't judge whether this definition defines the answer.
'arrange a second shipment' is the wordplay.
I cannot really understand how this works, but
'arrange' could be 'order' (synonyms) and 'order' is present in the answer.
'second' could be 're' (prefix meaning second in eg review, re-education) and 're' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for reorder that I've seen before include "Send off again for" , "Rearrange" , "Again apply for" , "requisition another!" , "Arrange afresh" .)