Invalidate second article taken out of yearbook (5)
I believe the answer is:
annul
'invalidate' is the definition.
(synonyms)
'second article taken out of yearbook' is the wordplay.
I cannot really understand how this works, but
'article' could be 'an' (indefinite article) and 'an' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for annul that I've seen before include "Cancel or render void" , "scratch" , "Obligation" , "Scrap" , "Recall" .)