1: Lifeblood of dope (3)

3: Irish playwright livin soundly (5)

5: Nits are possibly more unpleasant (7)

7: Dressing of malt and beans to make horse tender (9)

9: Freedom of action in desert (7)

11: Dance with Oliver (5)

12: How to get around doing business, essentially (3)

1: Vice exploits body cavities (7)

2: Infection leads from partly uncooked steak (3)

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

4: Rabbit (male) with nest of bunnies? (5)

6: They occupy the space of many workers (7)

8: Hand calculators, starting as backups, add critical information (5)

10: Small piece of fish (3)