### Clue: Fine line shown in proposal for one making late arrival on the square? (9)
### Answer: TAILENDER 
 ### Explanation: Definition: one making late arrival on the square
 [ AI(A1/the best quality/fine, with the Roman numeral substitution) + L(abbrev. for "line") ] **contained in**(shown in) TENDER(a proposal/an offer in response to, well, a tender).
Defn: The batsman in a cricket side who is the last in to bat/the last batsman to enter the square/the rectangular central part of a cricket field used as the pitch between the wickets – rectangular square?