1. In medicine, the fertilization of the ovum by the spermatozoon, occurring in the human female usually about the twelfth to fifteenth day after the first day of menstrual flow.
2. The use of a word that relates to, qualifies, or governs two or more other words but agrees in number, gender, or case with only one of them: "Neither my wife nor I want to" is an example of syllepsis, where "want" agrees with "I" but not "wife".
3. The use of a word that relates to, qualifies, or governs two or more other words but has a different meaning in relation to each; for example, "Mary picked up her coat and a ride home."