·add. ·noun A sexual cell or germ cell; a conjugating cell which unites with another of like or unlike character to form a new individual. In Bot., gamete designates ·esp. the similar sex cells of the lower thallophytes which unite by conjugation, forming a zygospore. The gametes of higher plants are of two sorts, sperm (male) and egg (female); their union is called fertilization, and the resulting zygote an oospore. In Zool., gamete is most commonly used of the sexual cells of certain Protozoa, though also extended to the germ cells of higher forms.