The pointer East in numbered ends has tapered (8)
I believe the answer is:
narrowed
'tapered' is the definition.
(I've seen this before)
'the pointer east in numbered ends' is the wordplay.
'the pointer' becomes 'arrow' ('arrow' can be a synonym of 'pointer').
'east' becomes 'e' (synonyms).
'in' means one lot of letters goes inside another.
'ends' means to remove the middle letters.
'numbered' with its centre removed is 'nd'.
'arrow'+'e'='arrowe'
'arrowe' inserted into 'nd' is 'NARROWED'.
'has' acts as a link.
(Other definitions for narrowed that I've seen before include "Shrank from" , "Grew less wide" , "Tapered" , "Reduced in width" , "grew closer" .)