Articles about singular, extinct bovid in reference work (9)
I believe the answer is:
thesaurus
'reference work' is the definition.
(thesaurus is a kind of reference work)
'articles about singular extinct bovid' is the wordplay.
'articles' becomes 'the a' (two grammatical articles).
'about' is an insertion indicator.
'singular' becomes 's' (abbreviation sometimes used in dictionaries).
'extinct bovid' becomes 'urus' (urus is a kind of bovid. I am not sure about the 'extinct' bit.).
'thea' enclosing 's' is 'thesa'.
'thesa'+'urus'='THESAURUS'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for thesaurus that I've seen before include "Word book" , "Reference book" , "Word-finder" , "work we may refer to" , "lists?" .)