Clockwise round the grid from 11 run three trios (8,4,6,5,9,3,5,8,4), each trio combining to suggest the same word. A trio of unclued lights combine to give a relevant activity (hyphened) and the remaining unclued light gives a relevant name verifiable in Brewer.
 

Across

9    Hat to be pleased with resembling a boater (10)
13    Sculptor and angler on good terms (5)
14    Brutes rector needles and opposes manfully (7)
15    Brilliant discoveries including European object (round) (7)
17    Brother painting timeless exotic shrubs (10)
19    Experiment involving El Salvador for example (5)
22    Rotter beginning to irk judge (4)
26    Courts have the Queen meeting fifth of judges (5)
28    Brown sauces Noel’s pages stirred (10)
31    Virago’s hankie (3)
33    Judge acting cold with aristo (7)
34    Mechanical instrument I see (7)
36    Female artiste trashed poet’s undress (9)
37    Bias of newspapers covering constabulary body (10)
 

Down

1    Plans yobbos always concealed (7)
2    Popular scene becoming visible (6, two words)
3    Native of Bordeaux buries a rubidium deposit (9, hyphened)
4    Small children Italian old master captures (5)
5    Unacceptable Cuban heel damaged pub furniture (8)
6    Plots calm king probes (5)
7    Good goblin into dressing up (5)
8    Our Levi’s, dyed initially, came up deep pink (7, two words)
10    A police station tracking knight’s sword (6)
12    Chatterbox displaying periodical confusion (6)
18    Savage criminal seizes poet’s husband set off in pursuit! (9, two words)
20    Trees deep among rocks (6)
21    Restless mosaicist lacking a quiet fortitude (8)
23    Naughty Iris hums endlessly in study periods (7)
24    Nameless unsafer moneylender (6)
27    Wrongful purpose of vicious menacers with clubs out (7, two words)
29    Senile Scots tour SA twice (6)
30    As an unpopular speaker, perhaps missing lecturer ran away (5)
32    A new day in France ending early in old province there (5)
33    Morons judge snubbed (5)
 
A first prize of £30 for the first correct solution opened on 16 January. 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 2290, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.