Nothing like exists in spring (5)
I believe the answer is:
oasis
'spring' is the definition.
(I've seen this before)
'nothing like exists' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'like' becomes 'as'.
'exists' becomes 'is' (if something 'is', it exists).
'o'+'as'+'is'='OASIS'
'in' acts as a link.
(Other definitions for oasis that I've seen before include "Fertile tract in a desert" , "Spring of fresh water in a desert" , "Fertile place like waterhole in desert" , "Peaceful area away from trouble" , "Place of peace" .)