End nomad wandering when needed (2,6)
I believe the answer is:
on demand
'when needed' is the definition.
'end nomad wandering' is the wordplay.
'wandering' is an anagram indicator.
'end'+'nomad'='endnomad'
'endnomad' anagrammed gives 'ON DEMAND'.
(Other definitions for on demand that I've seen before include "Whenever required" , "As soon as required" , "When asked for" , "As soon as requested" .)