Last solution

Across: 1 Appendix; 5 Heal; 9 Fret; 10 Strategy; 11 Alter; 12 Nominal; 13 Exceptionally; 18 Confound; 19 Send; 20 Special; 21 Begun; 22 Dull; 23 Symmetry.

Down: 2 Perplex; 3 Extreme; 4 Intentionally; 6 Eternal; 7 Loyalty; 8 Layman; 13 Excused; 14 Congeal; 15 Profit; 16 Austere; 17 Langour.