WordNet sense 1 ((surgery) tissue or organ transplanted from a donor to a recipient; in some cases the patient can be both donor and recipient):

transplant, transplant

WordNet sense 2 (cause to grow together parts from different plants):

engraft, ingraft

WordNet sense 3 (the practice of offering something (usually money) in order to gain an illicit advantage):

bribery

WordNet sense 4 (the act of grafting something onto something else):

grafting