What is the meaning of work up?

verb

• Form or accumulate steadily.
  • usage: "Resistance to the manager's plan built up quickly"; "Pressure is building up at the Indian-Pakistani border"
  • synonyms: build up, build, progress
• Develop.
  • usage: "we worked up an as of an appetite"
  • synonyms: get up
• Bolster or strengthen.
  • usage: "We worked up courage"; "build up confidence"; "ramp up security in the airports"
  • synonyms: build up, build, ramp up
• Come up with.
  • usage: "His colleagues worked out his interesting idea"; "We worked up an ad for our client"
  • synonyms: work out