Siamese cat
slug
A Sock.
Waist coat
Excessive sweat.
school diploma
huge shotguns
Second birthday.
Some three letter words starting with "s" are:sacsadsagsapsatsawsayseaseesetsewsexsheshysinsipsirsitsixslysobsodsonsopsotsowsoyspaspystysuesumsun
CAT scan. Coughing seniors.
All I can think of is "seance collaborator."
Some four letter words starting with S and ending with F are:selfserfsurf
A couple of cars had two words starting with S in their names. The first is the Saab Sonett, which was made from 66-74. Also Chevrolet had a trim level of the Monte Carlo called the SS for Super Sport which had a larger engine than the basic Monte Carlo.