Frank Smith and others have recently made available a new Khmer-English online dictionary. It is searchable using either English, Khmer or the International Phonetic Alphabet. The interesting thing is that the dictionary itself is not new, rather it is a synthesis of three existing dictionaries…
These resources are primarily based on the two very different editions of the Cambodian-English Dictionary: Cambodian-English Dictionary by Robert K. Headley, Kylin Chhor, Lam Kheng Lim, Lim Hak Kheang, and Chen Chun (1977, Catholic University Press), and Cambodian-English Dictionary by Robert K. Headley, Rath Chim, and Ok Soeum (1997, Dunwoody Press, ISBN 0-931745-78-0)
The 1977 edition draws heavily on traditional Cambodian lexicography; in particular, on the monumental Chuon Nath dictionary (see below). With some 20,000 headwords and almost 25,000 subentries, it is notable for its phonemic and grammatical analyses. Headley ‘77 also provides extensive etymological references, with nearly 10,000 Pali and Sanskrit citations, and hundreds more from Thai, Cham, French, Vietnamese, and a dozen other languages.
The 1997 edition contains more than 50,000 entries. It was compiled with an emphasis on the modern languge, particularly modern words, and expressions used in both written and spoken Cambodian. However, it also contains many entries for literary and poetic forms, and can be used to help in reading classic Cambodian texts. It has less etymological information than the ‘77 edition, but include far more usage (e.g. social level) tagging, and more than two thousand example sentences.
Searches in Khmer orthography will also return entries from the Chuon Nath Khmer Dictionary (1966, Buddhist Institute, Phnom Penh). This classic work represents the high point of pre-war Cambodian lexicography.
Khmer language input uses the Khmer Unicode font system. If you have not installed it yet, Windows users should see the KhmerOS site for download and installation instructions. Linux users can track down the language packages in the repositories. In addition to Khmer Unicode font use in particular programs, Khmer translations are maintained for the Kubuntu andopenSUSE Linux distributions (maybe others?).