Santa, Snow, Sledge, Sleigh, Stocking, many more
StreamSheetSpearSlimeSweetSweat
garlands
Bellybuttons would be the longest word I can think of beginning with a 'b' and ending in an 's'.
shawl
Seven.
Santa
Seta is a 4-letter word for hair or bristle starting with S.
Sincere is an adjective. It begins with the letter s.
StreamSheetSpearSlimeSweetSweat
sum
The word you are looking for is "sap."
so
spotless
set
silence
dauntless
runners