Lives initially documented by science-fiction writer (6)
I believe the answer is:
dwells
'lives' is the definition.
('dwell' can be a synonym of 'live')
'initially documented by science-fiction writer' is the wordplay.
'initially' says to take the initial letters.
'by' says to put letters next to each other.
'science-fiction writer' becomes 'wells' (herbert george wells).
The initial letter of 'documented' is 'd'.
'd'+'wells'='DWELLS'
(Other definitions for dwells that I've seen before include "Lodges or resides" , "pauses" , "Establishes oneself" , "Lives in, inhabits" .)