Wiktionary
n. (context pharmaceutical drug English) Any antibiotic that is active against a wide range of bacteria, especially against both gram-positive and gram-negative bacteria.
Wikipedia
The term broad-spectrum antibiotic refers to an antibiotic that acts against a wide range of disease-causing bacteria. A broad-spectrum antibiotic acts against both Gram-positive and Gram-negative bacteria, in contrast to a narrow-spectrum antibiotic, which is effective against specific families of bacteria. An example of a commonly used broad-spectrum antibiotic is ampicillin.
Usage examples of "broad-spectrum antibiotic".
They knew that what they'd come up with might be the last broad-spectrum antibiotic for a generation.
Tom injected him with a broad-spectrum antibiotic and an antimalarial.
Moi administered an intravenous injection of a strong broad-spectrum antibiotic.
I found what I wanted in a snap compartment: a blister pack of Cipro, a powerful broad-spectrum antibiotic.
She sorted through her First Aid kit to make certain no one had mistaken pills for the coffee candy that her survival gear also contained, popped two painkillers anyway, along with a broad-spectrum antibiotic, and waited for the headache to subside.