SOLUTION BELOW
ACROSS
1 Threaded fastener (5)
4 With no chance of being successful or winning (3,2,3,7)
14 Noisy fight (5)
15 Worth (5)
16 Tautology (10)
17 Surpass (5)
19 Donkey (3)
20 Pursued stealthily (7)
21 Essential (9)
22 Baited (6)
25 Ruler (9)
27 Lyrical (6)
28 Night-time howler (6)
33 Wooden eating utensils (10)
35 Fled (3)
36 Tobacco user (6)
37 Pleased (4)
39 One of the Seven Dwarfs (3)
41 Advantage (7)
42 Edible tuber (6)
43 One who maintains a collection of records (9)
44 Agrarian (5)
45 Spicy (8)
50 Egyptian sun god (2)
51 Fair (8)
55 Snow house (5)
58 Play scenery mover (9)
59 Diminished (6)
60 Plodded wearily (7)
61 Distress code (3)
63 Fish traps (4)
64 Fanatic (6)
65 Digit (3)
66 Bid taker (10)
68 Tagged (anag)(6)
69 Felt compassion for (6)
71 Cooking implement (6,3)
76 Chief manservant (6)
77 Cheerfully irresponsible (9)
79 Tramp (7)
81 Zero (3)
84 Snow-rain mixture (5)
85 Amendment (10)
86 Foe (5)
87 Precise (5)
88 Extremely pale (2,5,2,1,5)
89 Sea mammal (5)
DOWN
2 Sly (6)
3 Peer (5)
5 Unlock (4)
6 Floating cold lump (7)
7 Cooking-pot stand (6)
8 Leaves (5)
9 Disconcert, rattle (7)
10 Poverty (4)
11 Atom cores (6)
12 Cold dish (5)
13 Experienced sailor (3,4)
14 Fruit flower (7)
18 One on foot (10)
23 Roost (5)
24 Of crucial importance (7)
26 Subjugate (7)
27 In Greek mythology, the first mortal woman (7)
29 Temperature scale (7)
30 Food from milk (6)
31 Court hearing (5)
32 Cleric (6)
34 Flue deposit (4)
36 Derision (5)
38 Old-fashioned (5)
40 Short skirt (4)
45 Girl's name (5)
46 Modified (7)
47 Is indebted to (4)
48 Rubbed out (6)
49 Explosion (5)
50 Oven-cooked (7)
52 City in England (10)
53 Supplements to a book (7)
54 Cricket team (6)
55 Halcyon (7)
56 Tossed pole (5)
57 Greek B (4)
62 Pungent (5)
67 Amalgam user (7)
68 Smiled broadly (7)
70 Black-market (7)
72 Chapter (anag)(7)
73 Precious stones (6)
74 Film holder (6)
75 Smooth hard coating (6)
76 Become swollen (5)
78 Weatherproof garment (5)
80 Large American farm (5)
82 Hankering (4)
83 Expectation (4)