keep in a certain state, position, or activity; e.g., "keep clean"; "hold in place"; "She always held herself as a lady"; "The students keep me on my toes"
keep in safety and protect from harm, decay, loss, or destruction; "We preserve these archeological findings"; "The old lady could not keep up the building"; "children must be taught to conserve our national heritage"; "The museum curator conserved the ancient manuscripts"
supply with necessities and support; "She alone sustained her family"; "The money will sustain our good cause"; "There's little to earn and many to keep"