Each of the eight unclued lights is a series of letters in alphabetical order which can be formed into eight theme words. Elsewhere, ignore two accents.
 

Across

1    Book from Goon, having siesta disturbed (12)
10    Second-in-command’s deviant practice (4)
12    Gave permission and reportedly went under, getting ignored (10)
14/40     French pal, tense, at heart in his city (6)
18    A lad — Tim — composed Dahl musical (7)
22    Fields entered by sportsmen, finally (6)
24    On outskirts of Evesham, encountered Cornish tourist (5)
26    Writers taking a fizzy drink in the Florida Panhandle (9)
27    See a trick re-presented by lutz performer (3-6)
29    Speedy aunt regularly appearing in carriage (5)
31    Well-groomed engineer comes back after most of the evening in 14/40 (6)
34    Show embarrassment as run ended in distress (6)
36    Bitter maple starts to bloom in Canada (7)
40    See 14
41    Mariner’s stress spoken of when not taking alcohol (10)
42    Direct approach (4)
43    Expressing disapproval about one losing value (12)
 

Down

2    Marks of damage reported from more macabre moments (10)
3    Moon vehicle supported by China? One misjudges landing! (7)
4    Native Israeli overturned wheeled carriages (5)
5    Intoxication from tiny beer I ordered (9)
6    Tubes — Cornish painting’s turned up (6)
7    Red dye is one newly produced (5)
8    Persistent strife of vassal’s tenure with duke (4)
9    Useful point on Dark Blue university society (12)
11    Like a road’s edge in small county, partly tapered (8)
13    Heavenly demo shortened — one round Calais (12)
16    Secretive and silly, oddly (3)
20    32 now remade as gun, say (6)
21    Pacific islander at Hindu fair turning insane (10)
23    Rex left exotic dancer confused about a short narrative (9)
25    It kills snakes for money — peso mostly turned up (8)
32    Vegetable and fruit cut, and another cut twice (3)
33    Rocky ridge — one first reached before summer in France (5)
35    A lot of jealousy over one final stanza (5)
37    Vehicles cruising along Baker Street at first (4)
 
A first prize of £30 for the first correct solution opened on 12 March. There are two runners-up prizes of £20. (UK solvers can choose to receive the latest edition of the Chambers dictionary instead of cash — ring the word ‘dictionary’.) Entries to: Crossword 2347, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.