<p><strong>Noun</strong></p><ul><li>a colorless, crystalline, slightly water-soluble antibiotic, C₁₁H₁₂Cl₂N₂O₅, obtained from cultures of <em>Streptomyces venezuelae</em> or synthesized.</li><li>used chiefly in the treatment of infections caused by certain bacteria, by rickettsiae, and by certain viruses.</li></ul>