Webster's Revised Unabridged Dictionary · 1913

Antibacterial

Antibacterial , adjective

(a)
(Medicine) killing or inhibiting the growth of bacteria; -- applied also to serum for protection against bacterial diseases.
(b)
(Medicine) Opposed to the bacterial theory of disease. [archaic]

Antibacterial , noun

(Medicine) a chemical substance which kills or inhibits the growth of bacteria.