Hhhmmmm......... Got to be the CRUST
The crust of the bread stops the spread.
You tread on the Earth's crust.
In the rhyme "Sing a Song of Six Pence" the birds begin to sing when the pie (crust) was opened and it was considered a dainty dish for the king.
credit given where credit is due: thanks Carey for the first 2 lines.
blackjack
flooble's webmaster puzzle