The same 26 appears six times in 1D. Remaining unclued lights exemplify its different meanings. The 26 will appear diagonally in the completed grid and must be shaded.
 

Across

7    Chief cycling daily (4)
11    Young man has time for special author (5)
12    Food Victor feeds forces (6)
13    A road alongside hill in Cheshire? (7)
15    Heart of some lady fair (4)
17    Maybe Oxford lecturer has eyepiece with unique cavity (10)
18    Water casks? Take in large cups (8)
21    Birds from region around Germany (5)
22    Friend hoards money in an unfriendly way (7)
23    Rory downsized huge cargo boats (5, hyphened)
29    Sheep in wood heard (3)
33    Strengthen sewer in Strand (5)
35    Sly thief has skill in card game (7)
37    Employed suit lied when working (8)
38    Cheery Bob rallied round Papa (computers terrify him) (10)
41    Gypsy is cross across in Golden State (7)
42    Fink in jumper backing Cicero? (6)
43    Drug consisting of powder (not Charlie) (5)
44    Oxen performed somersaults (4)
45    Innovative newcomer producing green claret (10, two words)
 

Down

2    Organ’s no export from abroad (4)
3    Idly mooch and possibly pen a part song (10, two words)
4    Pie with egg and never chips? (7)
5    Diseases from beetles we eradicated (5)
6    El Salvador admits champion we expel (8)
8    Dance away and repeat rapidly (7, two words)
9    Bluff cardinal fond of painting? (6)
10    Cook too much in contemplation of party (6)
14    Arboreal beast in acacia starts to like acer (5)
19    Note fish in stream (3)
20    Pound had comical sort of metre (10)
27    Tonic you finish off in wrestling ring (5)
28    A pirate gang capsized in rough sea (7)
30    Spiteful snake in Equality State (5)
31    Amphibian forsook no lake (3)
32    Buying piece of meat in Crosby? (7)
34    Bedchamber of game French female (6)
35    Hen bit engaging child (6)
37    Freedom to sing without end in Uruguay (5)
39    Composer of note almost humble (4)
 
A first prize of £30 for the first correct solution opened on 24 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 2304, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.