According to SOWPODS (the combination of Scrabble dictionaries
used around the world) there are 13 words with the pattern
-E----SIS. That is, nine letter words with 2nd letter E and 7th
letter S and 8th letter I and 9th letter S. In alphabetical order,
they are:
aesthesis
geognosis
hematosis
hemolysis
heterosis
keratosis
melanosis
metabasis
nephrosis
periapsis
pertussis
resinosis
selenosis