Celebrity Squares: Each reference indicated thus must be replaced by a surname (usually ignoring capitalisation). The initial letters of the corresponding forenames can be rearranged to reveal O, popularly identified with X. Solvers must use X's name to complete the unclued entries, and indicate X's college and year.

The winner of this month's crossword was David Howell (Jesus College, 1971).

Dec 2013 Crossword

Across

4 One often before 6 -formerly with X, and reportedly in Oxford? (9)

10 Oxonians start building network (3)

11 Large vessel finally in marina, no longer at sea (5)

13 Stops loose ends getting inside harvesting machinery (6)

16 Party leader (Wadham 1931) forsaking wind instrument for stringed one (4)

18 Shelter PM (Christ Church 1805) retiring penniless (3)

20 Regularly in denial about situation (3)

22 Change from D to F for several notes (6)

24 Condiment ultimately wanted badly (4)

25 Body part cut from poor PM (Somerville 1937) (5)

26 Medical term for bones found in glossary (4)

32 Gains overall acceptance ultimately among Scottish conservationists (4)

35 Doing convoluted figure in spherical geometry (5)

36 Last English river sport (4)

37 Dug around river in Italy, finding container for drink (6)

38 Little creature sheltered by children’s campaigner (Somerville 1959) (3)

39 Old unit employed by astronomer (Queen’s 1673) making comeback (3)

40 Enormous clasp on end of necklace (4)

41 Misrepresent protégé of evolutionist (Balliol 1959) (5)

42 Unfortunately they are overlooking hotel restaurant (6)

45 Is art perfected in poet (University 1971)? (5)

47 Great friend of O, by study obsessed (3-6)

48 Someone snooping around outside – corgi finally barks (4)

Down

1 Saw vacuous film star (New College 1979) getting feminist author (New College 1985) down? (7)

2 One temptation that’s said to diminish (5)

3 Bad woman and mother – almost abandoned X, for example (12)

4 Raised at last, goose with gold eggs (3)

5 Turns up in tears after starting argument (7)

7 Drop Liberal Minister (Magdalen 1990) – not delivered? (4)

8 Upset, as film’s making claim that’s patently untrue (7)

9 Soirée ending with hostess (Oriel 2004) tottering around in scary fashion (6)

12 Crafted rightly, some provides setting for diamonds (12)

17 Top quality 32, if unorthodox (6)

19 Warning in book’s conclusion food writer (LMH 1979) partly crossed out (6)

21 Captive politician is not kept in shackles, perhaps (6)

23 Bottom of car doors splattered at first in dirt (6)

27 Where poet and author (Magdalen 1874) was shut away in study (7)

29 Atone for taking pieces of art from one living abroad (7)

30 Plans day playing tennis outside (7)

31 Cane initially supporting one like O (6)

33 Dispersed, or led a charge one more time? (6)

38 Gold coins a politician and novelist (St Anne’s 1965) hid now and then (5)

39 Small case is partly destroyed beneath reversing truck (4)

43 Some writing material for PM (Christ Church 1788) (3)