Biter's viper sliding around before noon (7)
I believe the answer is:
vampire
'biter's' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'viper sliding around before noon' is the wordplay.
'sliding' is an anagram indicator (letters sliding around).
'around' means one lot of letters goes inside another.
'before noon' becomes 'AM' (as in AM on a clock).
'viper' is an anagram of 'vpire'.
'vpire' going around 'am' is 'VAMPIRE'.
Can you help me to learn more?
(Other definitions for vampire that I've seen before include "Corpse that rises at night to drink the blood of the living" , "Nosferatu, for example" , "Type of bat" , "Transylvanian bloodsucker" , "A blood-sucker like Dracula" .)