Hard to believe, as a tale (4)
I believe the answer is:
tall
'hard to believe as a tale' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tall that I've seen before include "Vertically large" , "Lofty; unlikely" , "description of a giraffe?" , "that's hard to swallow" , "Higher than the average person" .)