This page provides a list of all the dictionaries used over the years on Countdown, and when they were in use.
Series 1 Prelim 1 (02/11/82) to Series 20 Prelim 12 (18/07/90) - Concise Oxford Dictionary (7th Edition) (COD7)
Series 20 Prelim 13 (19/07/90) to Series 30 Grand Final (29/09/95) - Concise Oxford Dictionary (8th Edition) (COD8)
Series 31 Prelim 1 (01/01/96) to CoC X Grand Final (31/12/99) - Concise Oxford Dictionary (9th Edition) (COD9)
Series 42 Prelim 1 (03/01/00) to Series 42 Prelim 6 (10/01/00) - Concise Oxford Dictionary (10th Edition) (COD10) *
Series 42 Prelim 7 (11/01/00) to Series 42 Grand Final (23/06/00) - Concise Oxford Dictionary (9th Edition)
Series 43 Prelim 1 (26/06/00) to Series 50 Grand Final (19/12/03) - New Oxford Dictionary of English (NODE)
Series 51 Prelim 1 (05/01/04) to Series 54 Grand Final (26/05/06) - Oxford Dictionary of English (2nd Edition) (ODE2)
CoC XII Prelim 1 (29/05/06) to Series 63 Grand Final (17/12/10) - Oxford Dictionary of English (2nd Edition revised) (ODE2r)
Series 64 Prelim 1 (10/01/11) to date - Oxford Dictionary of English (3rd Edition) (ODE3)
Masters Series 1, M1 to M52 (03/04/89 to 30/03/90) - COD7
Masters Series 2, M53 to M64 (02/04/90 to 22/06/90) - COD7
Masters Series 2, M65 to M104 (25/06/90 to 29/03/91) - COD8
Countdown at Christmas (25/12/97) - COD9
Celebrity Countdown (23/04/98 to 18/06/98) - COD9
Specials, S1 to S25 (26/05/03 to 30/05/05) - NODE
Specials, S26 to S29 (15/03/10 to 16/08/10) - ODE2r
Special, S30 to S31 (14/03/11 to 25/07/11) - ODE3
* after ROADSIDE was disallowed in Series 42 Prelim 4 (a decision which led to champion Helen Wrigglesworth being prematurely knocked out), COD10 was deemed unsuitable for use on Countdown when it was realised that many compound words were no longer specified in the dictionary. COD9 was returned to use three shows later.