Sailor on about newspaper showing herb (8)
I believe the answer is:
tarragon
'herb' is the definition.
(I know that tarragon is a type of herb)
'sailor on about newspaper' is the wordplay.
'sailor' becomes 'tar' (tar can mean a sailor).
'about' means one lot of letters go next to another.
'newspaper' becomes 'rag' (informal term for a newspaper).
'on' after 'rag' is 'ragon'.
'tar'+'ragon'='TARRAGON'
'showing' is the link.
(Other definitions for tarragon that I've seen before include "Aromatic herb used in cooking" , "Herb coming" , "Culinary herb" , "Arrogant (anag) - herb" , "seasoning" .)