"Small" prefix for scope (5)
I believe the answer is:
micro
'small prefix for scope' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for micro that I've seen before include "Prefix meaning tiny, or one-millionth of a unit" , "minute" , "needed in kitchen-sink dramas?" , "Very little" , "Extremely small" .)