According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 34 words with the pattern --N-S-. That is, six letter words with 3rd letter N and 5th letter S. In alphabetical order, they are:
agnise
banish
bonism
bonist
danish
dynast
eonism
finest
finish
funest
honest
ionise
kinase
lanose
linish
minish
mongst
monish
monism
monist
monosy
nanism
nonuse
panisc
panisk
punish
renest
sanest
tanist
tonish
unnest
vanish
venose
winish