What is meant by the term 'broad spectrum antibiotics'?

The term broad-spectrum antibiotic can refer to an antibiotic that acts on the two major bacterial groups, gram-positive and gram-negative or any antibiotic that acts against a wide range of disease-causing bacteria.

It means that the antibiotics which kill or inhibit a wide range of harmful or disease-causing bacteria. These are equally effective against gram positive and gram negative bacteria (both).

Examples: Ampicillin and Amoxycillin.