Sounds like somewhere one could find jumpy characters - one living off the other (8)
I believe the answer is:
parasite
'one living off the other' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'sounds like somewhere one could find jumpy characters' is the wordplay.
I cannot really see how this works, but
'like' could be 'as' and 'as' is found within the answer.
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for parasite that I've seen before include "Relies on host to survive" , "One living off another" , "it sucks blood" , "host has to put up with" , "unwanted guest" .)