NINCOM
NINCOMPOOP
NINCOMPOOPERIES
NINCOMPOOPERY
NINCOMPOOPS
NINCOMS
NINCUM
NINCUMS
NINE
NINEBARK
NINEBARKS
NINEFOLD
NINEHOLES
NINEPENCE
NINEPENCES
NINEPENNIES
NINEPENNY
NINEPIN
NINEPINS
NINES
NINESCORE
NINESCORES
NINETEEN
NINETEENS
NINETEENTH
NINETEENTHLY
NINETEENTHS
NINETIES
NINETIETH
NINETIETHS
NINETY
NINHYDRIN
NINHYDRINS
NINJA
NINJAS
NINJITSU
NINJITSUS
NINJUTSU
NINJUTSUS
NINNIES
NINNY
NINNYHAMMER
NINNYHAMMERS
NINNYISH
NINON
NINONS
NINTH
NINTHLY
NINTHS

49 words start with NIN.