What is the meaning of Apheresis?

Elision, suppression, or complete loss of a letter or sound (syllable) from the beginning of a word, such as the development of special from especial; procope.

The removal of blood from a patient, and the removal of certain components (such as platelets) from that blood, followed by the transfusion of the filtered blood back to the donor (patient).

Extirpation or extraction of a superfluity (especially a pathological one) from the body, especially blood.

Source: wiktionary.org