Eight unclued entries are of a kind. A 9-letter word for their position must be highlighted in the grid.
 

Across

1    Am being harassed by society celebs (8, two words)
5    Idiots half-heartedly following British and Russian decrees (6)
9    Surer 4, strangely unsure (10)
14    Fitting carpet, ignoring odd bits (3)
16    Nobody initially criticises young female on piano (6)
17    Philosopher stopped ball, removing clothes (5)
18    Game companion set to include this (5)
20    Top-class loot in province and city of Africa (7)
22    Extract from Telegraph on iatrogenic voice loss (7)
26    Head of History Department advancing in profundity (5)
28    Push forward, destroying redoubt (7)|
31    Father of monasticism, extremely angular at lowest point (7)
33    Embarrassed a bogus journalist (7)
37    University dons strike back in attacks (5)
38    Retired north-eastern gentleman got up (5)
39    Laughing out loud, cut and run (6)
41  Those without vice train Norse monks (10, hyphened)
42    Took long steps in straight lines (6)
43    Central themes of books occupying economist (8)
 

Down

1    I bribe tall lad to play ball game on this (13, two words)
3    Unlimited waste, here and behind (6)
4    Poet rejecting thin material (5)
6    Band of Yale entrants? (7, two words)
7    Instruct porpoises, perhaps (6)
8    Sheepish female burglar finally in jug (4)
10    Ravel content to leave Ukrainian granny? (6)
11    Irregular cricket match in Morecambe covered by news agency (9)
12    Ace criminal barristers possessing popular capricious quality (13)
13    Putsch permits poetry (8)
15    Cheap ricotta containing fruit (7)
19    Italian playwright working flat out, overstepping the mark (9, two words)
21    Yeoman of the Guard releasing fine bird (8, hyphened)
29    Place to sleep undisturbed is necessity at first for nomad (6)
30    We hear someone lamenting ship (6)
32    Lecture English Romeo, regularly wearing sporran inside out (6)
35    Terribly easy time, till now (5, two words)
 
A first prize of £30 for the first correct solution opened on 22 April. 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 2402, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.