Verb
keep in safety and protect from harm, decay, loss, or destruction
keep informed
prevent from going to bed at night
maintain a required pace or level
lengthen or extend in duration or space
Source: WordNetNo matter how cynical you become, it's never enough to keep up. Lily Tomlin
Never try to impress a woman, because if you do she'll expect you to keep up the standard for the rest of your life. W. C. Fields
It's no good trying to keep up old friendships. It's painful for both sides. The fact is, one grows out of people, and the only thing is to face it. W. Somerset Maugham
It takes good memory to keep up a lie. Pierre Corneille
Never keep up with the Joneses. Drag them down to your level. Quentin Crisp
Keep up with the times, don't stay in the dark. Sicilian Proverb