nad

1 of 2

noun (1)

variants or less commonly nard
plural nads also nards
informal + impolite
: testis
usually used in plural
: a coenzyme C21H27N7O14P2 of numerous dehydrogenases that occurs in most cells and plays an important role in all phases of intermediary metabolism as an oxidizing agent or when in the reduced form as a reducing agent for various metabolites

called also nicotinamide adenine dinucleotide, diphosphopyridine nucleotide, DPN

Word History

Etymology

Noun (1)

short for gonad

Noun (2)

nicotinamide adenine dinucleotide

First Known Use

Noun (1)

1964, in the meaning defined above

Noun (2)

circa 1962, in the meaning defined above

Time Traveler
The first known use of nad was circa 1962

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Cite this Entry

“Nad.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nad. Accessed 12 Mar. 2026.

Medical Definition

NAD

1 of 2 noun
: a coenzyme C21H27N7O14P2 of numerous dehydrogenases that occurs in most cells and plays an important role in all phases of intermediary metabolism as an oxidizing agent or when in the reduced form as a reducing agent for various metabolites

called also diphosphopyridine nucleotide, DPN, nicotinamide adenine dinucleotide

NAD

2 of 2 abbreviation
no appreciable disease
Last Updated: - Entry added
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