n.fertilization of two or more ova released during the same menstrual cycle by sperm from separate acts of coitus (especially by different males)
英汉双解大词典
superfecundation/ˌsuːpəˌfiːkənˈdeɪʃən/
1.
N（名词）
the fertilization of two or more ova, produced during the same menstrual cycle, by sperm ejaculated during two or more acts of sexual intercourse 同期复孕 [physiol]