self-fertilizationnoun [ U ]
specialized UK usually self-fertilisation uk/ˌself.fɜː.tɪ.laɪˈzeɪ.ʃən//ˌself.fɝː.t̬ə.ləˈzeɪ.ʃən/the process in which a seed or egg starts developing into a new plant or animal after joining with a male cell from the same plant or animal, rather than a different one
self-fertilize
verb [ I ] UK usually self-fertilise uk/ˌselfˈfɜː.tɪ.laɪz//ˌselfˈfɝː.t̬əl.aɪz/
He let the yellow pea plants self-fertilize to see what the second generation would look like.