Primate kept up by weird nightmare (5)
I believe the answer is:
indri
'primate' is the definition.
(indri is a kind of primate)
'up by weird nightmare' is the wordplay.
'INDRI' is hidden backwards within the letters.
However, I am uncertain how this is indicated.
'kept' acts as a link.
Can you help me to learn more?
(Other definitions for indri that I've seen before include "Large Madagascan lemur" , "large primate" , "Species of lemur" , "Big Madagascan lemur" , "Short-tailed lemur of Madagascar" .)