The synonym is "saying" - the meaning of "saw" is an old proverb or truism.
Other synonyms might be shibboleth or slogan.
Substantial is a synonym for big that starts with S.
Synonyms for news beginning with S include: scuttlebutt story
"Scout out" is a synonym for "check out" that starts with 's' and has the 'ou' sound.
Subtle
The synonym is "saluted" in the sense of applauding an action.
sailor, shipmate, seafarer
Sailor is a synonym for mariner.
savor
synonym
Spear is a synonym for lance. It begins with the letter S.
scene, sign
scope ?