Disease observed while pulling back fleshy part of ear at midday (5)
I believe the answer is:
ebola
'disease' is the definition.
(I have seen 'Deadly disease ' mean 'ebola' so perhaps 'disease' could also mean 'ebola')
'observed while pulling back fleshy part of ear at midday' is the wordplay.
I cannot really see how this works, but
'part' could be 'la' (la is a kind of part) and 'la' is present in the answer.
'of' could be 'o' and 'o' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ebola that I've seen before include "Congolese river - serious virus disease" , "Source of virus" , "Deadly disease" , "Infectious fever" .)