Dictionary.net

increase or strengthen gradually; "This investment is building interest"; "We worked up courage"

grow or intensify; "Pressure is building up at the Indian-Pakistani border"

enlarge, develop, or increase by degrees or in stages; "build up your savings"

change the use of and make available or usable; "develop land"; "The country developed its natural resources"; "The remote areas of the country were gradually built up"

bolster or strengthen; "We worked up courage"; "build up confidence"; "ramp up security in the airports"

prepare oneself for a military confrontation; "The U.S. is girding for a conflict in the Middle East"; "troops are building up on the Iraqui border"