Expert standing beside a large old member of cattle family (7)
I believe the answer is:
buffalo
'member of cattle family' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'expert standing beside a large old' is the wordplay.
'expert' becomes 'buff' (buff can mean an expert or aficionado).
'standing beside' is a charade indicator (letters next to each other).
'large' becomes 'L' (eg in clothes sizes).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'buff'+'a'+'l'+'o'='BUFFALO'
Can you help me to learn more?
(Other definitions for buffalo that I've seen before include "US bison - upstate New York port" , "Bovid animal" , "American horned beast" , "Horny beast" , "Ox with swept-back horns" .)