measles
Are you sure it ends in S? I am thinking jail, but if it ends in S it could be mess, pens, cans.
A 13-letter word that starts with "s" and ends with "s" is "schoolteachers."
Scissors is an 8 letter word. It begins and ends with S.
Sandman (starts with S ends with N - 7 letter word)
An eight letter word that starts with S and ends with T: satiristshortestsmallestsmarteststagnantstalwartstiffeststridentsubtract
6 letter word that ends in s and is a unit of measurement: ounces
Sansansiding.
gladiolus
slopslurpstopstumpstepstoopslapstompshopshipsipsnapsapsleepsloopsupsoapslipskipsoupstamp
satisfactions
shortstops
seamanship