Decorator suffering from infectious disease in Dublin
I believe the answer is:
paintbrush
'decorator' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'suffering from infectious disease in dublin' is the wordplay.
'suffering' becomes 'pain' (I've seen this before).
'from' means one lot of letters go next to another.
'infectious disease' becomes 'tb' (TB is an example).
'in dublin' becomes 'rush' (I can't justify this - if you can you should believe this answer much more).
'pain'+'tb'+'rush'='PAINTBRUSH'
Can you help me to learn more?
(Other definitions for paintbrush that I've seen before include "applicator such as this" , "Artist's applier" , "Artist's tool" .)