Endless nonsense is eschewed by all? (5)
I believe the answer is:
alone
'eschewed by all?' is the definition.
(ignored or avoided by everyone)
'endless nonsense' is the wordplay.
'endless' means to look at the middle letters.
'nonsense' becomes 'baloney' (baloney is a kind of nonsense).
The middle of 'baloney' is 'ALONE'.
'is' acts as a link.
(Other definitions for alone that I've seen before include "Exclusively, by oneself" , "without partner?" , "Singly" , "Note of charges" , "Exclusively; solitary" .)