Together with the British scholar Malcolm Guthrie (1903–1972) he is regarded as one of the two leading experts in Bantu languages in the second half of the 20th century.
[2][3] A. E. Meeussen studied classical philology at the Catholic University of Louvain (Leuven) in Belgium, where he submitted his PhD thesis on Indo-European ablaut in 1938.
[2][3] Among the Bantu languages which Meeussen described or studied were Luba-Kasayi (1951), Ombo (1952), Kirundi (1952), Laadi (1953), Bangubangu (1954), Bemba (1954), Luganda (1955), Shambala (1955), Sotho (1958), Lega (1962), Tonga (1963), and Yao (1971).
His descriptions of the grammar of Ombo, Bangubangu, and Rundi were written as a result of fieldwork notes which he made on a visit to Rwanda-Urundi and Maniema district of the Belgian Congo in 1950-51; the information on Lega was obtained from visitors to the Museum.
[4] His 40-page article "Bantu Grammatical Reconstructions" of 1967 succinctly outlines the main facts of Proto-Bantu grammar as they were known at that time.