a silver-white alloy containing copper and zinc and nickel
nickel steel
Noun
an alloy steel containing nickel
nicotinamide adenine dinucleotide
Noun
a coenzyme present in most living cells and derived from the B vitamin nicotinic acid
nicotinamide adenine dinucleotide phosphate
Noun
a coenzyme similar to NAD and present in most living cells but serves as a reductant in different metabolic processes
nitride
Noun
a compound containing nitrogen and a more electropositive element (such as phosphorus or a metal)
nitrobenzene
Noun
a poisonous oily water-soluble liquid used as a solvent and in the manufacture of aniline
nitrofuran
Noun
derivative of furan used to inhibit bacterial growth
nitrogenase
Noun
an enzyme of nitrogen-fixing microorganisms that catalyzes the conversion of nitrogen to ammonia
nuclease
Noun
general term for enzymes that catalyze the hydrolysis of nucleic acid by cleaving chains of nucleotides into smaller units
nucleic acid
Noun
(biochemistry) any of various macromolecules composed of nucleotide chains that are vital constituents of all living cells
nucleoside
Noun
a glycoside formed by partial hydrolysis of a nucleic acid
nucleotide
Noun
a phosphoric ester of a nucleoside
nurse log
Noun
a large decomposing tree trunk that has fallen, usually in a forest
nitrogen trichloride
Noun
a yellow pungent volatile oil (trade name Agene) formerly used for bleaching and aging flour
natural rubber
Noun
an elastic material obtained from the latex sap of trees (especially trees of the genera Hevea and Ficus) that can be vulcanized and finished into a variety of products
neoprene
Noun
a synthetic rubber that is resistant to oils and aging
notepad
Noun
a pad of paper for keeping notes
nitrate
Noun
any compound containing the nitrate group (such as a salt or ester of nitric acid)
nitrate
Verb
treat with nitric acid, so as to change an organic compound into a nitrate
nitro group
Noun
the group -NO3
nitrite
Noun
the radical -NO2 or any compound containing it (such as a salt or ester of nitrous acid)
nonsteroid
Noun
an organic compound that does no contain a steroid
nephrotoxin
Noun
any toxin that affects the kidneys
neurotoxin
Noun
any toxin that affects neural tissues
neurolysin
Noun
any toxin that affects neural tissues
nitramine
Noun
a yellow crystalline explosive solid that is used in detonators
niacin
Noun
a B vitamin essential for the normal function of the nervous system and the gastrointestinal tract
naphthoquinone
Noun
a fat-soluble vitamin that helps in the clotting of blood
natrolite
Noun
a group of minerals of the zeolite family consisting of a hydrous silicate of sodium and aluminum
neonatal period
Noun
the first 28 days of life
note value
Noun
(music) the relative duration of a musical note
nonce
Noun
the present occasion
nineties
Noun
the time of life between 90 and 100
nineties
Noun
the decade from 1990 to 1999
nineties
Noun
the decade from 1890 to 1899
nonage
Noun
any age prior to the legal age
noon
Noun
the middle of the day
noonday
Noun
the middle of the day
noonday
Adjective
of or at the middle of the day
noontide
Noun
the middle of the day
nighttime
Noun
the time after sunset and before sunrise while it is dark outside
nightfall
Noun
the time of day immediately following sunset
name day
Noun
the feast day of a saint whose name one bears
new moon
Noun
the time at which the Moon appears as a narrow waxing crescent
new phase of the moon
Noun
the time at which the Moon appears as a narrow waxing crescent
national holiday
Noun
authorized by law and limiting work or official business
New York minute
Noun
a very short time (as the time it takes the eye to blink or the heart to beat)