Bipod
A bipod is a supporting structure with two legs that contact the ground, connected to the object being supported. Think of it as an inverted "V" shape, with the supported object being at the apex.
A bipod is not independently stable, and requires some additional support or control. For example, a bipod mount for a machine gun, placed under the muzzle, reduces the weight that the soldier must lift and stabilizes the weapon. That gun, however, is not stable unless the soldier holds and guides the other end.
The connection between the bipod and the supported object may be rigid, so that all lateral and tilt movement must be manual, or it may be a swivel joint, allowing continued support without moving the bipod proper.
Bipedal movement
In biology, a bipedal organism, such as a human being, balances on two legs. As with the mechanical support, it is an inherently unstable support, so the organism must sense its position and make balancing movements.