✨📕 The NEWThe NEW Collegiate Dictionary, 12th Edition Over 5,000 words added — Buy Now! Collegiate DictionaryBuy Now!

penicillin G

noun

: the penicillin C16H18N2O4S that constitutes the principal or sole component of most commercial preparations and is used chiefly in the form of its stable salts (as the sodium salt C16H17N2NaO4S or potassium salt C16H17KN2O4S)

called also benzylpenicillin

see penicillin g benzathine, penicillin g procaine

Browse Nearby Words

Cite this Entry

“Penicillin G.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/penicillin%20G. Accessed 29 Nov. 2025.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!