Occasional piece of furniture displays every element (8,5)
I believe the answer is:
periodic table
'every element' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'occasional piece of furniture' is the wordplay.
'occasional' becomes 'periodic' (I've seen this before).
'piece of furniture' becomes 'table' (table is a kind of piece of furniture).
'periodic'+'table'='PERIODIC TABLE'
'displays' acts as a link.
Can you help me to learn more?
(Other definitions for periodic table that I've seen before include "Chart of elements" , "List of elements arranged by atomic number" , "Elementary information" , "List of chemical elements" , "Elementary list" .)