Watercourse appearing in Maori verse (5)
I believe the answer is:
river
'watercourse' is the definition.
(I know that river is a type of watercourse)
'in maori verse' is the wordplay.
'in' indicates the answer is hidden within the clue.
'RIVER' can be found hidden inside 'maori verse'.
'appearing' is the link.
(Other definitions for river that I've seen before include "Dee, Exe or Wye, say" , "Exe, Po" , "Large natural stream of water" , "Cam?" , "Eg, Severn" .)