That is 'bipedalism'.
The bending of an arm or leg is called flexion.
Creatures that walks on two legs are called bipeds.
gibbet |ˈjibit| historicalnouna gallows.• an upright post with an arm on which the bodies of executed criminals were left hanging as a warning or deterrent to others.• ( the gibbet) execution by hanging : the four ringleaders were sentenced to the gibbet.
Upright.
gnomon
gnomon
The raised arm of a sundial that indicates the time of day by its shadow is the gnomon (NO-mon). A sundial has but one arm, what do you mean by secondary arm?
The raised arm of a sundial that indicates the time of day by its shadow is the gnomon (NO-mon). A sundial has but one arm, what do you mean by secondary arm?
the shadow of the sundial is just called a shadow
The gnomon is the indicator on a sundial.
A gnomon is the upright piece of a sundial, and it is the part that casts its shadow down onto the dial to indicate local solar time.
Gnomon
The first type of clock was called a sundial, and the oldest sundial dates back to around 1500 BC.
It is called a Gnomon
Gnomon
humans and other creatures that walk upright are called