According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 7 words with the pattern C-N-I-S. That is, seven letter words with 1st letter C and 3rd letter N and 5th letter I and 7th letter S. In alphabetical order, they are:
candids
candies
condies
confits
congius
conoids
cundies