1. The omission at the beginning of a word as in "coon" for "raccoon" or "till" for "until" or "special" for "especial" or "squire" for "esquire" or "count" for "account" or "cause" for "because".
2. A procedure in which blood is drawn from a donor and separated into its components, some of which are retained, such as plasma or platelets, and the remainder returned by transfusion to the donor.