a hollow metal tube, usually made of stainless steel and sharpened at one end
a thin, hollow needle attached to a syringe; used to inject a medication under the skin, into a vein, or into a muscle
A needle inserted through the skin to introduce drugs into the subcutaneous layer.
A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body. They may also be used to take liquid samples from the body, for example taking blood from a vein in venipuncture.