A sharp point covered by fabric (6)
I believe the answer is:
tartan
'fabric' is the definition.
(tartan is a kind of fabric)
'a sharp point covered' is the wordplay.
'sharp' becomes 'tart' (I've seen this before).
'point' becomes 'n' (North).
'covered' indicates putting letters inside.
'tart'+'n'='tartn'
'a' inserted into 'tartn' is 'TARTAN'.
'by' acts as a link.
(Other definitions for tartan that I've seen before include "Distinctive pattern of Highland clan as seen in kilt" , "Scots cloth pattern" , "Highland check pattern" , "Symbol of the Scottish clans." , "(Fabric with) distinctive checked pattern" .)