illuviation Syllabification: (il·lu·vi·a·tion)Pronunciation: /iˌlo͞ovēˈāSHən/Definition of illuviation noun Soil Science the introduction of salts or colloids into one soil horizon from another by percolating water. Derivatives illuvialPronunciation: /iˈlo͞ovēəl, -vyəl/ adjective illuviatedPronunciation: /iˈlo͞ovēˌātid/ adjective Origin: early 20th century: from il- 'in' + -luvial (on the pattern of alluvial) + -ationilluviation in other Oxford dictionaries Definition of illuviation in the British & World English dictionary