PANTALOONS, n. A nether habiliment of the adult civilized male. The garment is tubular and unprovided with hinges at the points of flexion. Supposed to have been invented by a humorist. Called "trousers" by the enlightened and "pants" by the unworthy.
2008 Update: A sheath for the sensible side of a human, inhibiting flight and so requiring negotiation.