Merriam-Webster Collegiate Dictionary

The Merriam-Webster Collegiate Dictionary (MWCD) was first published by Merriam-Webster in 1898 and is now in its 11th edition.

Its current edition has always been one of the source lexicons for the OSPD and OTCWL. Until the publication of the Long List, it was also used as a supplementary word reference for base words too long to be listed in the primary reference, and their inflections of similarly excessive length. So during the OSPD era, words of 9 or more letters had to be checked first in OSPD and then in MWCD; the occasional word of 8 or fewer letters (either base word or inflection) unique to MWCD would not be considered acceptable. In the subsequent OTCWL era, similarly for words of 10 or more letters and 9 or fewer letters.

The ultimate reasons for the shift to a SCRABBLE-specific long word reference were as follows:

• general dictionaries do not explicitly list all inflections, often making adjudications difficult and subject to directorial judgement
• general dictionaries do not necessarily list inflections near their base words: the most famous example being the plural EMALANGENI of the word LILANGENI
• MWCD is updated continually online, and its printings vary in their content within an edition
• using multiple sources for short words and a single source for long words led to a discontinuity in the feel of the lexicon

11th Edition

The 11th Edition was published in 2003, was used from 2004–2013 as the word reference for longer words in the School SCRABBLE Program, and was a source lexicon for OTCWL2014.

10th Edition

The 10th Edition was published in 1994. From 1994–05–01 to 1998–02–28, it was the supplementary word reference to OSPD2. From 1998–03–01 to 2006–06–13, it was the supplementary word reference to OTCWL1.

9th Edition

The 9th Edition was published in 1983. From an unknown date soon after its publication to 1991–09–30, it was the supplementary word reference to OSPD1. From 1991–10–01 to 1994–04–30, it was the supplementary word reference to OSPD2.

8th Edition

The 8th Edition was published in 1973. From 1978–09–01 to an unknown date in the 1980s, it was the supplementary word reference to OSPD1. It was succeeded in this role by the 9th Edition. Prior to its adoption, word of all length were adjudicated using the Funk and Wagnalls Standard College Dictionary (1973 edition).