Facing nasty snakes you and I may show timidity (8)
I believe the answer is:
weakness
'timidity' is the definition.
(thesaurus)
'facing nasty snakes you and i' is the wordplay.
I cannot really see how this works, but
an anagram of 'snakes' is 'akness' which is within the answer.
'you and i' could be 'we' and 'we' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'may show' is the link.
Can you help me to learn more?
(Other definitions for weakness that I've seen before include "Defect" , "Fault or flaw" , "Vulnerability" , "Ill-defended spot - predilection" , "Infirmity" .)