A small sealed glass container for holding a liquid medicine, vaccine, or other substance; a variant spelling of ampoule.
Variant shortening of ampoule, from Latin ampulla. Different English-speaking regions prefer different spellings (ampul vs. ampoule), much like color/colour.
American pharmacists often write 'ampul' while British ones might write 'ampoule'—it's the same tiny glass bottle, just dressed in different spelling clothes across the Atlantic.
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