nail polish, or just nails.
In fashion
a word that starts with k and ends in n is known
Another word for addition which starts with the letter N is New.
Nefertiti is an Egyptian god that starts with n.
Outre - something that is overdone.
Sandman (starts with S ends with N - 7 letter word)
nonintervention
November
"Narc"
nuzzle
novel
A four letter word that starts with g and ends with n is gown :)