Unwavering fellow found in ground, as stated (9)
I believe the answer is:
'unwavering' is the definition.
(I know that unwavering can be written as steadfast)
'fellow found in ground as stated' is the wordplay.
'fellow' becomes 'f' (abbreviation - of a society etc.).
'found in' means one lot of letters goes inside another.
'ground' indicates anagramming the letters ('grind' the letters into a new form).
'asstated' with letters rearranged gives 'steadast'.
'f' going inside 'steadast' is 'STEADFAST'.
(Other definitions for steadfast that I've seen before include "Firm, fixed and faithful" , "stable" , "Firm and unwavering" , "Sure" , "Constant, not changing or yielding" .)