Thelma or Ian sheltering a New Zealander (5)
I believe the answer is:
maori
'a new zealander' is the definition.
(I've seen this before)
'thelma or ian sheltering' is the wordplay.
'sheltering' indicates the answer is hidden within the clue.
'MAORI' is hidden in the letters of 'thelma or ian'.
(Other definitions for maori that I've seen before include "Original New Zealanders" , "A native from the south" , "native people" , "antipodean language" , "I roam with New Zealander" .)