1: Proficient in arithmetic, starting with short division (5)

3: Grant loud colour (3)

5: Mention bum Ford model? (5)

7: Three kernels of copper-yellow grain (3)

8: Very clever fish ain't at sea (9)

10: It comes to a point everyone heard (3)

11: Lethargic entertainer taking part (5)

12: Uninitiated stoop to finish (3)

13: Grand space for bride's mate (5)

1: Unscripted part for head librarian (2,3)

2: Exciting object getting rent by stream (9)

3: Grass present round container (7)

4: Sound of river crossing (3)

6: Suppressed and overturned, it's taken flight (7)

9: Lug worm finally being a symbol (5)

10: Consumed and digested tea (3)