Copied article removed from each reference book (6)
I believe the answer is:
echoed
'copied' is the definition.
(I've seen this before)
'article removed from each reference book' is the wordplay.
'article' becomes 'a' (example of the part-of-speech).
'removed from' is a deletion indicator.
'reference book' becomes 'oed' (I can't justify this - if you can you should believe this answer much more).
'each' with 'a' taken out is 'ech'.
'ech'+'oed'='ECHOED'
Can you help me to learn more?
(Other definitions for echoed that I've seen before include "said nothing original" , "copied" , "Reverberated; repeated" , "Repeated a sound" , "Rang" .)