Top team occasionally ignored linesman (6)
I believe the answer is:
tabard
'top' is the definition.
(I've seen this before)
'team occasionally ignored linesman' is the wordplay.
'occasionally ignored' indicates alternate letters (ignore occasional letters and keep the rest).
'linesman' becomes 'bard' (bard is a kind of poet).
The alternating letters of 'team' are 'ta'.
'ta'+'bard'='TABARD'
(Other definitions for tabard that I've seen before include "Inn where pilgrims met" , "Coat worn by herald" , "Sleeveless jacket" , "Short sleeveless tunic" , "[A] top" .)