The unclued lights (one of three words and two of two words), individually or as a pair, are of a kind.
 

Across

 
5    Bit of tiffin is hardly perfect (6)
12    Fail to see active service (5)
13    Waistcoat cloth that’s not in ablutions (8)
16    Beer mug in set cracked (5)
17    Mourns for old sheriffs (7)
18    Additionally suggest Tory memo (7)
20    Civic dignitary, a lord, with topless Berliner, say (8)
26    Extra portion of lamb? Yes! (3)
27    Tailless bird – dead duck in the Loire (6)
29    Aussie expert involved with 8 for 1A (3)
30    Notice amateur point out adjustment (8)
36    Ill-defined mixture with half the relish (7)
39    Girl in NE Scotland removing bit of core from fruit (5)
41    Panorama is a winner in Virginia (5)
43    Resort town – SE Somerset town (6)
44    Comic poet off-centre at end of game (7)
 

Down

 
1    Harm mother’s generation (6)
2    Enjoyed time with saucy dates (6)
3    More prying riled senior (6)
4    One cross – one caught showing no sign of life (5)
6    In torpid lethargy (4)
8    Ground for building is odd to see, we’re told (4)
9    Settlers smarting badly (8)
11    Stories about double-agents without U-boat (7)
14    Press club (4)
16    Chinese shrubs accompanying frail boats in rhyme (11, two words)
19    Bread not available about noon (4)
21    Join up with some middlemen (4)
23    Dark-haired thug got into difficulty. Quite the opposite (8)
24    Advise against, we’re told, being diminished by decay (7, two words)
25    College Society going round flashy or dull spots (6)
26    Prevent Cambodia leaving political association (4)
30    MacTavish takes the minutes (4)
31    Penny’s dingy Scottish cream jug (6)
32    Set on fire wood that’s left out (6)
33    Unite and split (6)
35    Entrails from river (5)
37    Half the Finnish epic for the meal in Scotland (4)
38    Fragrant oil from Weaver’s heart (4)
 
A first prize of £30 for the first correct solution opened on 2 February. 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 2194, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.