Definitions by Urchin

Most clues are of the Definition and Letter Mixture type, which contain a definition of the answer and a jumble of its letters. Of these 19 contain an extra letter in the mixture. These letters, in normal clue order, should help with the other clues. Finally, solvers should highlight two words (7, 6) to confirm the theme.

1 A dead sinner, revised and edited (5)
6 Type of mistress most gentlemen prefer (6)
10 Minutes it takes to catch a pike (4)
11 Flies or the food ant-eaters consume (7)
13 A tool to comb hair on the foot (8)
14 A forced landing suffered by one of low rank (5)
15 Sort of arch-fiend in a horror film (5)
18 How a car feels when it leaves a mark on a tree (4,4)
20 A product that is branded adversely (6)
21 One who promises that the answer is a lemon (6)
23 A fool considered under another aspect (6)
25 A method of untying with the teeth a political knot that would not yield to
the tongue (6)
27 When a stiff upper lip is more elusive (8)
31 A Moral Rearmament worker who delivers mail in the US (5)
33 One worthy of credit for the dissolution of parliament (5)
35 A girdle used for the prevention of uterine contraction (8)
36 A sweet substance obtained from octahedral iron ore (7)
37 The type of signals that can be made with Cuisenaire rods (4)
38 An ingenious device used by a man on the roof in Boulder Creek (6)
39 The outward and visible sign of an inward fear (5)
1 During Pentecost, sackcloth that is worn by a bishop (6)
2 A long vestment worn by the Icarian priests (4)
3 Copies, which, at a shorter distance, bear no resemblance to the originals
4 Describing a nation losing the struggle to succeed (4)
5 Boned wisdom for weak teeth (5)
6 A sort of fibropsammoma common among mothers in the US (6)
7 An eco-catastrophe that multinationals may thrust upon us (8)
8 Insensible to the value of our advice (4)
9 One appearing sane, whereas, in reality plumb loco (5)
12 Sort of pratt like Harrison! (4)
16 A passion that goeth before a sprawl (4)
17 The cloth that protects in atomic research (8)
18 A bricklayer's measure (3)
19 The weak argument that liberals usually advance (4)
22 A by-product of the arts of peace (3)
24 Patterns of one dimension in mineralogy (6)
26 The most senior member of the valets-de-chambre (6)
27 To pick someone's brains with your arm across the ocean (5)
28 To preach at the opening of a supermarket (4)
29 One who serves his country by residing abroad (5)
30 Plum duff cooked on the perfect hob (5)
32 A ceremony fixed by law, with the essential oil of sincerity carefully
squeezed out of it (4)
33 Using salt to season a sausage in Perth (4)
34 A disease that rages in the food industries (4)

To enter this competition send your solution, in list format, plus the 2 highlighted words, to before the 8th August 2008. The first correct entry picked will receive a copy of the latest edition of Chambers  Pocket Crossword Dictionary, which has been donated by the publishers.