Father's always ready for a half of beer (5)
I believe the answer is:
pater
'father's' is the definition.
(old-fashioned term for father)
'always ready for a half of beer' is the wordplay.
'always ready' becomes 'pat' (I've seen this in another clue. I am not sure about the 'always' bit.).
'for' is a charade indicator (letters next to each other).
'a half of' indicates taking half.
'beer' with half the letters taken is 'er'.
'pat'+'er'='PATER'
Can you help me to learn more?
(Other definitions for pater that I've seen before include "Our Father - . . . . . Noster" , "A posh father, from Latin" , "Taper away like father" , "Dad (Latin)" , "Walter --, English essayist; father" .)