It's called the sole of the foot.
(Other areas on the sole of the foot are specifically called the ball of the foot, the arch of the foot, toes and heel)
A fraction has two parts. On the top is the numerator, and on the bottom is the denominator. The line separating them is called the vinculum.
It is called a track
you might have your feet up in front of a fire or radiator
The number on the bottom of a fraction is known as the "denominator."
A foot fetish.
The bottom of your foot is called the sole or pad.
sole
The sole of the foot.
The bottom of the foot is called the sole.
The bottom of the dog's paw is called the pad.
the arch of your foot
the skull crusher
The bottom of the foot is commonly referred to as the sole.
The bottom of a bed is typically called the footboard. It is a panel that is situated at the foot end of the bed frame.
The stem.
It is called a deck.
A cat's foot is called a "paw." It includes the pads on the bottom of the foot, the claws, and the soft fur.