Support an entry for Chaucer in “Early English Style” (8)
I believe the answer is:
elegance
'style' is the definition.
(I've seen this before)
'support an entry for chaucer in early english' is the wordplay.
'support' becomes 'leg' (leg is a kind of support).
'entry for' indicates taking the first letters (the letter which acts as the entrance to the word).
'in' indicates putting letters inside.
'early english' becomes 'ee' (architectural abbreviation).
The initial letter of 'chaucer' is 'c'.
'leg'+'an'+'c'='leganc'
'leganc' inserted into 'ee' is 'ELEGANCE'.
(Other definitions for elegance that I've seen before include "Refinement in taste and dress" , "Fine quality" , "Fashionable grace" , "Sophistication" , "Refinement - grace" .)