number one

a.最重要的，头号的

nuclear-free, nucleate, nucleic acid, nucleolus, nucleus, nude, nudge, nudism, nudist, nudist camp (also nudist colony), nudity, nugatory, nugget, nuisance, null, nullification, nullify, nullity, numb, number, numberless, numbly, numbness, numeracy, numeral, numerate, numeration, numerator, numerical, numerically, numerous, numinous, numismatics, numismatist, numskull (also numbskull), nun, nuncio, nunnery, nuptial, nuptials,