One unclued light is the name of a drink which can be measured into three ingredients. Each ingredient has three definitions among the other unclued lights; unchecked letters of the nine lights in question are supplied by the puzzle’s title.

Across

1 Changing tack, see, I perform on rink? (8, hyphened)
8 Total power in reservoir (4)
12 Contemptuous expression in silence covered by hand (5)
14 Commend arrangement of test run (7)
16 Corridor without a key? (4)
18 Comedian Eddie’s last letter (6)
22 Allegation people inside prevent (8)
23 Intermingle in action in large public buildings (7)
25 Information in addition giving species of penguin (6)
27 Road around islands mostly cut (7)
33 In school eat excessive salt (6)
34 Crustaceans losing mobile parts of antennae (5)
37 Troy emptied by defeat, overwhelming one in callosity (7)
39 Spirited foes prepared for days of judgement (12, two words)
40 Genuine old Spanish coin (4)
41 Valuer fools person short of time (8)

Down

2 Get rid of mould (4)
3 Fiscal arbitration partly numerical (6)
4 Sailor with crest in trim (7)
5 Unlawfully entered health establishment, breaking course up (10)
6 Joined also to conserve northern river (7)
7 Knight gripped by more terrible zeal accepting zero carousing (11, three words)
8 Trouble worse for goat-antelope (5)
10 Ingenious old man with plug (6)
15 Proceedings strangely known beforehand (11)
19 Prevailing authorities ruined our revels, suppressing resistance (10)
20 Move faster round curve when showing feature of bicycle? (8, hyphened)
21 Blood cell issue a hospital raised and yet mishandled (9)
26 Inner part of solid substance, iron ore (7)
28 A vote opening for handsome young men (7)
29 Fellow right under sun in position (6)
30 Wide margins for clubs (6)
31 Arouse wandering tribes (6)
36 Enthusiastic about independence, tense amid drama (4)

A first prize of £30 for the first correct solution opened on 9 November. 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 2234, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.