Definition of "holotype"
holotype
noun
plural holotypes
(taxonomy) The single physical example (or illustration) of an organism used to formally describe the species (or lower-order taxon), subsequently to be kept as a reference.
Quotations
Primary types include holotypes, lectotypes, and neotypes, while all other types (e.g., paratypes) are secondary types. A holotype is a unique, name-bearing type specimen designated by the original author. The holotype is the single individual of a species that serves as a voucher for a given species name. A holotype can be designated only by the original author and in the publication in which that author established its name.
2005, David Grimaldi, Michael S. Engel, Evolution of the Insects, Cambridge University Press, page 35
The species to which the holotype belongs is then referred to by the name proposed by the author, at least when the same name has not previously been applied to another species. […] If his specimen is not the same species as any of the holotypes preserved in museums, he should prepare a description of his specimen and have it published with his proposed name for the new species or give it to a specialist who is interested in doing this.
2008, Charles W. Heckman, Encyclopedia of South American Aquatic Insects: Odonata - Zygoptera, Springer, page 3