Toppling finally, old cupboard with books on hit the printers (2,2,5)
I believe the answer is:
go to press
'hit the printers' is the definition.
The definition suggests a singular noun which matches the answer.
'toppling finally old cupboard with books' is the wordplay.
'finally' says to take the final letters.
'old' becomes 'o' (abbreviation).
'cupboard' becomes 'press' (term for a large cupboard).
'with' says to put letters next to each other.
'books' becomes 'ot' (abbreviation for Old Testament).
The last letter of 'toppling' is 'g'.
'o'+'press'='opress'
'opress' after 'ot' is 'otopress'.
'g'+'otopress'='GO TO PRESS'
'on' acts as a link.
Can you help me to learn more?
(Other definitions for go to press that I've seen before include "Of newspapers etc, commence printing" , "Start making an impression" , "Start publishing" .)