DCHP-1 Online
figure-(of-)four trap figure-4, figure-of-4, etc. 
a kind of deadfall (def. 1) or other trap having the triggers set in a figure 4, first used by the Indians. See picture at deadfall.
See also: deadfall ((n.)) (def. 1 and picture)
- 1743 (1949) One more trap their is a figure of 4 trap, which is 2 Logs Squar'd for the sides, and a Log for the top of one foot wide, which is call'd a figure of 4 trap being sett up with 3 sticks in the shape of a figure of 4 the top Log falls upon the Vermin which is the safest trap to Keep Vermin from being Eat.
- 1867 Others are caught in a kind of figure-of-4 trap, but by far the larger number are speared.
- 1907 In the "figure-of-four" traps, before the animal is caught it must seize the bait with its teeth and pull strong enough to set off the trap, whereas with the steel trap the mere fact of his coming to the doorway to smell insures his putting his foot in it. . . .
- 1936 The signs of that figure-4 trap could all be smoothed out. . . .
- 1743 (1949) One more trap their is a figure of 4 trap, which is 2 Logs Squar'd for the sides, and a Log for the top of one foot wide, which is call'd a figure of 4 trap being sett up with 3 sticks in the shape of a figure of 4 the top Log falls upon the Vermin which is the safest trap to Keep Vermin from being Eat.