What is "trap stairs"

Trap \Trap\, n. [OE. trappe, AS. treppe; akin to OD. trappe, OHG. trapo; probably fr. the root of E. tramp, as that which is trod upon: cf. F. trappe, which is trod upon: cf. F. trappe, which perhaps influenced the English word.]

1. A machine or contrivance that shuts suddenly, as with a spring, used for taking game or other animals; as, a trap for foxes.

   She would weep if that she saw a mouse Caught in a trap.
   --Chaucer.

2. Fig.: A snare; an ambush; a stratagem; any device by which one may be caught unawares.

   Let their table be made a snare and a trap.
   --Rom. xi. 9.

   God and your majesty Protect mine innocence, or I fall into The trap is laid for me!
   --Shak.

3. A wooden instrument shaped somewhat like a shoe, used in the game of trapball. It consists of a pivoted arm on one end of which is placed the ball to be thrown into the air by striking the other end. Also, a machine for throwing into the air glass balls, clay pigeons, etc., to be shot at.

4. The game of trapball.

5. A bend, sag, or partitioned chamber, in a drain, soil pipe, sewer, etc., arranged so that the liquid contents form a seal which prevents passage of air or gas, but permits the flow of liquids.

6. A place in a water pipe, pump, etc., where air accumulates for want of an outlet.

7. A wagon, or other vehicle. [Colloq.]
   --Thackeray.

8. A kind of movable stepladder.
   --Knight.

   Trap stairs, a staircase leading to a trapdoor.

   Trap tree (Bot.) the jack; -- so called because it furnishes a kind of birdlime. See 1st Jack.

n. stairs leading to a trapdoor