(1) Attachment of the blastocyst to the endometrium, and its subsequent embedding in the compact layer, occurring 6-7 days after fertilization of the oocyte in humans. (2) The process of placing a device or substance within the body, e.g., placement of a saline-filled device beneath the breast mound. (3) Insertion of a natural tooth into an artificially constructed alveolus. (4) Tissue grafting.transplantation.