1. Free from living germs of disease, fermentation, or putrefaction; sterile.
2. Designed to prevent infection from pathogenic microorganisms.
3. Free of pathogenic microorganisms: "They used aseptic surgical instruments."
4. Using methods to protect against infection by pathogenic microorganisms: "The doctor insisted on using aseptic surgical techniques."
5. Lacking animation or emotion: "She responded with an aseptic smile."