Last solution

Across: 1 Casual; 4 Derive; 9 Unprecedented; 10 Surfeit; 11 Error;

12 About; 14 Stoop; 18 Panic; 19 Extract; 21 Qualification; 22 Extend;

23 Chancy.

Down: 1 Course; 2 Superabundant; 3 Abele; 5 Element;

6 Interrogation; 7 Endure; 8 Petty; 13 Unction; 15 Opaque; 16 Remit;

17 Stingy; 20 Teach.