Take no notice of ogre in novel (6)
I believe the answer is:
ignore
'take no notice of' is the definition.
(to take no notice of something is to ignore it)
'ogre in novel' is the wordplay.
'novel' indicates anagramming the letters (letters in a new or novel order).
'ogre'+'in'='ogrein'
'ogrein' with letters rearranged gives 'IGNORE'.
(Other definitions for ignore that I've seen before include "Neglect" , "Fail to observe" , "Pass over" , "Spurn" , "Fail to notice (6)" .)