… unlimited by 100 pound and English sentimentality (7)
I believe the answer is:
treacle
'sentimentality' is the definition.
(treacle can mean sentimental speech)
'unlimited by 100 pound and english' is the wordplay.
I cannot really see how this works, but
'100' could be 'c' (Roman numeral) and 'c' is present in the answer.
'pound' could be 'l' (abbreviation e.g. Lsd - pounds, shillings, pence) and 'l' is found in the answer.
'english' could be 'e' (abbreviation) and 'e' is present in the answer.
This explanation may well be incorrect...
(Other definitions for treacle that I've seen before include "cloying stuff" , "Sticky produce" , "Syrup-like substance" , "refined product" , "Carroll's sisters had to live with" .)