According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 6 words with the pattern -OP-I-R. That is, seven letter words with 2nd letter O and 3rd letter P and 5th letter I and 7th letter R. In alphabetical order, they are:
copsier
hoppier
loppier
moppier
poppier
soppier