First of all, some tabloid, appallingly shabby it seems is where circulation has dropped to zero (6)
I believe the answer is:
stasis
'where circulation has dropped to zero' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'first of all some tabloid appallingly shabby it seems' is the wordplay.
'first of all' indicates taking the first letters.
The initial letters of 'some tabloid appallingly shabby it seems' is 'STASIS'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for stasis that I've seen before include "absence of change" , "Assist with stagnant condition" , "Period of inactivity" , "State of inactivity where nothing moves" , "lack of progress" .)