Person of virulent hatred's extreme contempt about poison occasionally ignored (8)
I believe the answer is:
scorpion
'person of virulent hatred's extreme' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'contempt about poison occasionally ignored' is the wordplay.
'contempt' becomes 'scorn' (synonyms).
'about' indicates putting letters inside.
'occasionally ignored' means one should take alternating letters (ignore occasional letters and keep the rest).
The alternate letters of 'poison' are 'pio'.
'scorn' placed around 'pio' is 'SCORPION'.
Can you help me to learn more?
(Other definitions for scorpion that I've seen before include "Poisonous arachnid" , "Venomous stinger" , "Arachnid with venomous sting" , "Small lobster-shaped animal" , "Eight sign of Zodiac, kind of spider" .)