(biology) Any haplontic organism; any organism whose zygotes undergo zygotic meiosis (meiosis immediately after the fusion of cell nuclei).
1933, John Milton Webber, Cytological Features of Nicotiana Glucinosa Haplonts, M. C. Merrill (editorial supervisor), Journal of Agricultural Research, Volume 47, U.S. Department of Agriculture, page 864,
The behavior of haplont Nicotiana glutinosa is in harmony with the foregoing facts. […] The occurrence of diploid cells in the callus of decapitated haplonts may be attributed to causes similar to those resulting in diploid cells in proximal callus.