work up (v.)

1.develop"we worked up an as of an appetite"

2.come up with"His colleagues worked out his interesting idea" "We worked up an ad for our client"

3.form or accumulate steadily"Resistance to the manager's plan built up quickly" "Pressure is building up at the Indian-Pakistani border"

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