1 down. Something to sit on? 8 letters.
2 down. Recurring theme. 5 letters.
4 down. Inedible snaps (anag) – must-have. 13 letters.
5 down. Gut feeling. 5 letters.
6 down. Card game similar to rummy. 7 letters.
7 down. Soil-like material made from decaying plants. 4 letters.
8 down. Truly, madly or deeply – grammatically. 6 letters.
13 down. Very much. 8 letters.
15 down. Derange (anag) – political big beast. 7 letters.
16 down. Buster, Diane or Michael. 6 letters.
18 down. Open to bribery. 5 letters.
20 down. Steep-sided valley in the US. 5 letters.
21 down. French grey. 4 letters.