Across

The principal (full-length) film (7)
A set of three similar things considered as a unit (5)
A tiny or scarcely detectable amount (4)
10 A large landscaped gaming area (4,6)
11 Towed by a speedboat (5,3)
13 Physical damage to the body (6)
15 Adventures of a hero (4)
17 Completely opposed (5)
18 Restless desire (4)
19 Long and narrow (6)
20 Very nearly (4-4)
23 Openly distrustful (10)
26 Cry loudly, as of animals (4)
27 Greeting (5)
28 Deviation from the normal or common order or form or rule (7)

Down

Get rid of your junk (10)
A parasitic plant (6)
Ring recurrently; of bells (4)
Heavier and more compact in form or stature (8)
The function or position properly or customarily occupied or served by another (4)
All the plant life in a particular region (5)
A cloth for washing (7)
12 Relative by marriage (2-3)
14 A skilled worker (10)
16 The angle between the vertical plane and the plane of the meridian (7)
17 Cut from a hog (8)
21 Who grants a lease (6)
22 Lacking grace (5)
24 Very light colored (4)
25 A translucent mineral (4)