In surgery, a transplantation of tissue obtained from another of the same species: An allograft consists of a tissue graft from a donor of one species to a recipient of the same species, but not genetically identical or related.

An allograft is a tissue graft taken from a genetically nonidentical donor of the same species as the recipient.

An initial group of skin allografts which usually take and persist for several weeks in contrast to second-set allografts from the same donor.

The first-set allografts behave as an antigen so that the second-set allografts, when applied some weeks later, are rejected faster.