noun
[singular] the ability of your feet to stay where you put them as you walk, run, etc.
the condition of the ground that makes it easy or hard for your feet to stay where you put them as you walk or run
[singular] a - used to describe the kind of relationship that exists between people, countries, etc.; usually used with on
the base or foundation on which something is established :basis
usually used with on
[count] :the base or foundation on which a structure is built - usually plural