1. Introduction of a medicinal substance or nutrient material into subcutaneous tissue (subcutaneous or hypodermic injection), muscular tissue (intramuscular injection), a vein (intravenous injection), an artery (intraarterial injection), the rectum (rectal injection or enema), the vagina (vaginal injection or douche), the urethra, or other canals or cavities of the body. 2. An injectable pharmaceutical preparation. 3. Congestion or hyperemia.