booby trap = pitfall
Possible origins:
1) The booby trap name came from the skill of catching boobies - a sea bird, when out at sea. Bait would be placed in the middle of a noose; when the booby landed on deck to eat the food, the noose would be tightened to catch the bird by the legs.
2) Alternatively it could result from a derivative of the English usage of the term "boob": "an embarrassing mistake"