The List
There are 317 5 letter words with N as the first letter. The highest scoring is NUDZH at 18 points in Scrabble. 1 of them contain no vowel at all: NYMPH.
NAAMSNAANSNABESNABISNABKSNABLANABOBNACHENACHONACRENADASNADIRNAEVENAEVINAFFSNAGASNAGGYNAGORNAHALNAIADNAIFSNAIKSNAILSNAIRANAIRUNAIVENAKEDNAKERNAKFANALASNALEDNALLANAMEDNAMERNAMESNAMMANAMUSNANASNANCENANCYNANDUNANNANANNYNANUANAPASNAPEDNAPESNAPOONAPPANAPPENAPPYNARASNARCONARCSNARDSNARESNARICNARISNARKSNARKYNARRENASALNASHINASTYNATALNATCHNATESNATISNATTYNAUCHNAUNTNAVALNAVARNAVELNAVESNAVEWNAVVYNAWABNAZESNAZIRNAZISNEAFENEALSNEAPSNEARSNEATHNEATSNEBEKNEBELNECKSNEDDYNEEDSNEEDYNEELDNEELENEEMBNEEMSNEEPSNEESENEEZENEGUSNEIFSNEIGHNEISTNEIVENELISNELLYNEMASNEMNSNEMPTNENESNEONSNEPERNEPITNERALNERDSNERDYNERKANERKSNEROLNERTSNERTZNERVENERVYNESTSNETESNETOPNETTSNETTYNEUKSNEUMENEUMSNEVELNEVERNEVESNEVUSNEWEDNEWELNEWERNEWIENEWLYNEWSYNEWTSNEXTSNEXUSNGAIONGANANGATINGOMANGWEENICADNICERNICHENICHTNICKSNICOLNIDALNIDEDNIDESNIDORNIDUSNIECENIEFSNIEVENIFESNIFFSNIFFYNIFTYNIGERNIGHSNIGHTNIHILNIKABNIKAHNIKAUNILLSNIMBINIMBSNIMPSNINESNINJANINNYNINONNINTHNIPASNIPPYNIQABNIRLSNIRLYNISEINISSENISUSNITERNITESNITIDNITONNITRENITRONITRYNITTYNIVALNIXEDNIXERNIXESNIXIENIZAMNKOSINOAHSNOBBYNOBLENOBLYNOCKSNODALNODDYNODESNODUSNOELSNOGGSNOHOWNOILSNOILYNOINTNOIRSNOISENOISYNOLESNOLLSNOLOSNOMADNOMASNOMENNOMESNOMICNOMOINOMOSNONASNONCENONESNONETNONGSNONISNONNYNONYLNOOBSNOOITNOOKSNOOKYNOONSNOOPSNOOSENOPALNORIANORISNORKSNORMANORMSNORTHNOSEDNOSERNOSESNOSEYNOTALNOTCHNOTEDNOTERNOTESNOTUMNOULDNOULENOULSNOUNSNOUNYNOUPSNOVAENOVASNOVELNOVUMNOWAYNOWEDNOWLSNOWTSNOWTYNOXALNOXESNOYAUNOYEDNOYESNUBBYNUBIANUCHANUDDYNUDERNUDGENUDZHNUFFSNUGAENUKEDNUKESNULLANULLSNUMBSNUMENNUNNYNURDSNURDYNURLSNURRSNURSENUTSONUTSYNUTTYNYAFFNYALANYINGNYLONNYMPHNYSSA