oats
shut
spit
An eight letter word that starts with S and ends with T: satiristshortestsmallestsmarteststagnantstalwartstiffeststridentsubtract
im not sure about a 7 letter word, but i do know i 8 letter word that starts with s and means the right to vote, the word is... sufferage.
swim
That would be the word size.
sore
witswenswarswagswayswedswigswetswinswoeswuss
SUSSEX
oats
shut
Sperm
Sire
s for seek
Some four letter words beginning with P and ending with S:PadsPalsPansPapsParsPassPatsPawsPaysPeasPecsPegsPensPepsPetsPewsPicsPiesPigsPinsPipsPitsPlusPodsPolsPomsPopsPotsProsPubsPudsPugsPunsPupsPuts
pets