Light basket (7)
I believe the answer is:
'basket' is the definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?
'light' is the wordplay.
I cannot really see how this works, but
'light' could be 'set' (as in to set a fire) and 'set' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for cresset that I've seen before include "Strange secrets of the beacon" , "Fuel container" , "Formerly a light" , "Old form of illumination" , "Old torch" .)