Ship last icebox containing material that is not eco-friendly (7)
I believe the answer is:
plastic
'material that is not eco-friendly' is the definition.
'plastic' can be an answer for 'material' (I've seen this before). I am not certain of the remainder of the definition.
'ship last icebox containing' is the wordplay.
'containing' indicates the answer is hidden within the clue (I've seen 'contains' mean this).
'PLASTIC' is hidden in the letters of 'ship last icebox'.
Can you help me to learn more?
(Other definitions for plastic that I've seen before include "Ubiquitous synthetic material" , "Credit and debit cards" , "Generic name for certain synthetic materials" , "non-metallic material" , "means of deferring payment" .)