/ˌanīˈsägəmē/
Noun
1. Refers to a form of sexual reproduction involving the union or fusion of two dissimilar gametes (differing either in size alone or in size and form).The smaller gamete is considered to be male (sperm cell), whereas the larger gamete is regarded as female (egg cell). (wikipedia.org)
2. Condition in which gametes which fuse differ in size and/or motility. (biology-online.org)