2614: Monkey business

Unclued lights (one of three words and one of two words, singly or paired) form three groups. Group 1 is three words of a kind; group 2 is two names and a title; group 3 is a name and part of a title. The word that links them must be highlighted in the grid.

        Across

   8    Water sprite cut seaweed (4)

11    Man with publisher, old fool (5)

14    College has zero Asian money (5)

15    Laziness in Leeds is awful (7)

17    Welshman’s harp overturned (4)

19    Love poetry Auden’s beginning abroad (7)

23    Expelled journo pens adventure story (7)

24    In particle, track nucleus (6)

25    After dog, get a cuckoo in part of car (8)

26    Get radio set for insect (8)

27    Plagues reported in goosefoot plants (6)

34    Tiger, one by a fern (7)

35    Note American or Parisian beastly utterance (5)

36    Farm worker’s short buttercup (4)

39    Keralan people with a currency (5)

40    German agreed 11 keeps recalling game (3,4)

41    Phenol from poor cinnabar (5)

42    Really primitive and bitter (4)

43    Auditor’s calling for massage? (8)

         Down

   2    Go north around posh dwelling (4)

   3    US writer round king (1,5)

   4    Me, dead excited for award (6)

   5    Quatrain etc? This art fails (10)

   6    Crook’s dog all jittery (3,3)

   7    Film poster – shout it bags Oscar (5,6)

   8    Born in Malaysia’s capital, show respect (5)

   9    Measurer – it’s merely wrong (9)

10    Conduct piano live (7)

12    It’s played in irrational sports publication (4,5)

20    Beggar’s abdomen was treated (10)

21    Still clinging to first fact (9)

22    Join e.g.