Somewhat here, there, always immaterial (8)
I believe the answer is:
ethereal
'immaterial' is the definition.
(I've seen this in another clue)
'somewhat here there always' is the wordplay.
'somewhat' says the answer is hidden in the clue.
'ETHEREAL' is hidden within 'here there always'.
(Other definitions for ethereal that I've seen before include "Impalpable" , "'Fairy-like, delicate (8)'" , "Delicate and perfect" , "Delicate - airy" , "Airy or supernatural" .)