According to SOWPODS (the combination of Scrabble dictionaries
used around the world) there are 7 words with the pattern -OS-I-R.
That is, seven letter words with 2nd letter O and 3rd letter S and
5th letter I and 7th letter R. In alphabetical order, they are:
boskier
bossier
dossier
lossier
mossier
toshier
tossier