John, Abel's brother, about 55? (6)
I believe the answer is:
calvin
'john' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'abel's brother about 55?' is the wordplay.
'abel's brother' becomes 'cain' (biblical figure).
'about' indicates putting letters inside.
'55?' becomes 'LV' (Roman numerals).
'cain' going around 'lv' is 'CALVIN'.
Can you help me to learn more?
(Other definitions for calvin that I've seen before include "Reformation theologian" , "Christian theologian" , "John . . . . . ., French Protestant religious reformer of 16th century (6)" , "Geneva Reformation leader" , "Chief expositor of Presbyterian beliefs" .)