Letter from Eliot analysed (4)
I believe the answer is:
iota
'letter' is the definition.
(Greek letter)
'from eliot analysed' is the wordplay.
'from' indicates the answer is hidden within the clue.
'IOTA' is hidden in the letters of 'eliot analysed'.
(Other definitions for iota that I've seen before include "Gk. letter; tiny amount" , "Greek equivalent of the letter I" , "Greek letter - small quantity" , "Contrivance" , "Hint" .)