Outline of one book contained in rambling screed (8)
I believe the answer is:
describe
'outline' is the definition.
(I know that outline is a more specific form of the action describe)
'one book contained in rambling screed' is the wordplay.
'one' becomes 'i' (Roman numeral).
'book' becomes 'b' (abbreviation for book).
'contained in' indicates putting letters inside.
'rambling' indicates an anagram.
'i'+'b'='ib'
'screed' is an anagram of 'descre'.
'ib' placed inside 'descre' is 'DESCRIBE'.
'of' is the link.
(Other definitions for describe that I've seen before include "Give an account of extremely" , "Portray in words" , "Give verbal portrait of" , "Illustrate" , "style" .)