Not these (5)
'not these' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for those that I've seen before include "The (things) there" , "Ethos (anag.)" , "Nostalgic utterance" , "Plural form of that" , "The ones farther away" .)
(Other definitions for galah that I've seen before include "Fool" , "Simpleton" .)