straightjacket vs. straitjacket
sulfamethazine vs. sulfamezathine
synchronoscope vs. synchroscope
semitransparency vs. translucence
supernaturalism vs. supernaturalness
spontaneity vs. spontaneousness
surprisingness vs. unexpectedness
subjectiveness vs. subjectivity
singleness vs. straightforwardness
sanctimoniousness vs. sanctimony
slatternliness vs. sluttishness