"Hirudinal" is a term that refers to leeches or medications derived from leeches. Some synonyms for "hirudinal" include "sanguivorous," "bloodthirsty," and "leechlike." These words describe the blood-sucking behavior of leeches and can be used to describe medications that mimic their effects. Another synonym is "anticoagulant", which refers to the ability of leeches to prevent blood from clotting as they feed. Other words that can be used include "bloodsucker," "parasite," and "hematophagous." Despite their negative connotations, leeches and their derivatives have been used in medicine for centuries and still play a valuable role in modern clinical settings.