Here are some randomly selected joke topics beginning with the letter 'S'
Sad
What do fir trees do when they are sad?
They pine a lot.
Salad
What do you call a salad that is a coward?
A chicken salad.
Sail
Did you hear about the stupid yachtsman who had his arm cut off so that he could sail round the world single-handed.
Sailor
What do you get if you cross a tropical fruit with a cartoon character?
Papaya the Sailor Man.
Sailors
Did you hear about the man who thought Bob Marley and the Wailers were the sailors who caught Moby Dick?
Sad
Why was the calendar sad?
Because its days were numbered.
Safari
Did you hear about the ghost who last year went to Africa on safari?
He was a big-game haunter.