naf·cil·lin (năf'sĭl'ĭn)
n.
A semisynthetic, white to yellowish white powder, C₂₁H₂₁N₂NaO₅S, used as an antibiotic in severe staphylococcal infections.

[naf- (shortening and alteration of NAPHTHALENE) + (PENI)CILLIN.]

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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