Spear is a synonym for lance. It begins with the letter S.
Surface is a synonym for to appear. It begins with the letter S.
Stock is a synonym of product. It begins with the letter s.
Snow job is a synonym for deception. It begins with the letter S.
Stunning is a synonym for beautiful. It begins with S.
slim
sly
sympathy
Sailor is a synonym of mariner that begins with the letter S. Some others are salt, seafarer, shipmate, sea dog, shellback, and swabbie.
The synonym of "cosy" that begins with an "s" is "snug." Both words convey a sense of warmth, comfort, and being tucked in.
Scissors is an 8 letter word. It begins and ends with S.
Silver is a good conductor that begins with the letter "s".