It's different for some of the British (3)
I believe the answer is:
tis
'some of the british' is the definition.
I can't tell whether this definition defines the answer.
'it's different' is the wordplay.
'different' indicates an anagram (letters placed in a different order).
'its' with letters rearranged gives 'TIS'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for tis that I've seen before include "... the season to be jolly" , "Sequel to "Angela's Ashes"" , "I confirm the identity of" , "For poet, that's" , "That thing's" .)