autotetraploid
noun
au·to·tet·ra·ploid ˌȯ-tō-ˈte-trə-ˌplȯid 
: an individual or strain whose chromosome complement consists of four copies of a single genome due to doubling of an ancestral chromosome complement
autotetraploid adjective
autotetraploidy
ˌȯ-tō-ˈte-trə-ˌplȯi-dē
noun 
Word History
First Known Use
1930, in the meaning defined above