Arch pointed evenly on European river (5)
I believe the answer is:
rhone
'european river' is the definition.
(I've seen this before)
'arch pointed evenly' is the wordplay.
'evenly' indicates alternate letters (the letters in even-numbered positions).
'arch'+'pointed'='archpointed'
The alternating letters of 'archpointed' are 'RHONE'.
'on' acts as a link.
(Other definitions for rhone that I've seen before include "River running from the Swiss Alps to the Mediterranean" , "department" , "French river from Alps to Mediterranean" , "One following long course" , "River rising in Switzerland and flowing into the Mediterranean" .)