Rocker's equivalent to this roller? (7)
I believe the answer is:
trolley
'rocker's equivalent to this roller?' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'roller?' is the wordplay.
I cannot really understand how this works, but
'roller?' could be 'roll' (synonyms) and 'roll' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for trolley that I've seen before include "Wheeled handcart" , "Yell rot (anag.)" , "Supermarket mover" , "Wheeled table, cart" , "Handcart that holds groceries etc while shopping" .)