Grit shown by bandmate of D Crosby and S Stills (5)
I believe the answer is:
gnash
'grit' is the definition.
(I've seen this in another clue)
'bandmate of d crosby and s stills' is the wordplay.
I cannot quite understand how this works, but
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
's' is found in the answer.
The remaining letters 'gah' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'shown by' is the link.
Can you help me to learn more?
(Other definitions for gnash that I've seen before include "Hangs (anag.)" , "grinding action" , "Grind (teeth) together" , "Grind one's teeth" , "Grind away" .)