decimeter Syllabification: (dec·i·me·ter)Pronunciation: /ˈdesəˌmētər/ (British decimetre, abbreviation: dm)Definition of decimeter noun a metric unit of length, equal to one tenth of a meter. Derivatives decimetricPronunciation: /ˌdesəˈmetrik/ adjective decimeter in other Oxford dictionaries Definition of decimeter in the British & World English dictionary