His luck changed, close to someone similar (8)
I believe the answer is:
suchlike
'similar' is the definition.
(similar in meaning)
'his luck changed close to someone' is the wordplay.
'changed' indicates an anagram.
'close to' suggests the final letters (the close/ending of).
The final letter of 'someone' is 'e'.
'his'+'luck'='hisluck'
'hisluck' with letters rearranged gives 'suchlik'.
'suchlik'+'e'='SUCHLIKE'
(Other definitions for suchlike that I've seen before include "Things of the type mentioned" , "similar things" , "kindred" , "Of that kind; similar" .)