Alas, there are far too many.
fuss
witswenswarswagswayswedswigswetswinswoeswuss
oats
SUSSEX
pets
News Nibs Ness
Some four letter words beginning with P and ending with S:PadsPalsPansPapsParsPassPatsPawsPaysPeasPecsPegsPensPepsPetsPewsPicsPiesPigsPinsPipsPitsPlusPodsPolsPomsPopsPotsProsPubsPudsPugsPunsPupsPuts
STIX !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Could be a four letter word that starts with s and ends with x
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