Abel's dad (4)
I believe the answer is:
adam
'abel's dad' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for adam that I've seen before include "Robert -, Sc. architect" , "God's first son" , "expelled gardener" , "the first orphan?" , "According to the Bible, progenitor of the human race" .)