footing
Balance and stability when your feet are on something.
Footing means your balance and stability when you're standing or moving. When you have good footing on a hiking trail, your feet are planted firmly and you're not at risk of slipping. When you lose your footing on an icy sidewalk, your feet slide out from under you and you might fall.
The word comes from how well your feet grip the surface beneath you. Gymnasts need excellent footing on the balance beam. Rock climbers search carefully for solid footing on the cliff face. After a rainstorm, a muddy path offers poor footing because your shoes can't grip properly.
Footing also describes the basis or foundation of a relationship or situation. When two classmates start a friendship on equal footing, neither one has more power or advantage than the other. When you're on firm footing with a subject like multiplication, you understand it well enough to build on it. A business on shaky financial footing might be heading for trouble, just like a hiker with shaky physical footing might be about to stumble.
The word suggests stability and security, whether you're talking about actual feet on actual ground or the figurative ground beneath any situation.