What is the meaning of get on?

verb

• Have smooth relations.
  • usage: "My boss and I get along very well"
  • synonyms: get along with, get on with, get along
• Get on board of (trains, buses, ships, aircraft, etc..
  • synonyms: board
• Get up on the back of.
  • usage: "mount a horse"
  • synonyms: hop on, mount, mount up, jump on, climb on, bestride
• Grow late or (of time) elapse.
  • usage: "It is getting on midnight-let's all go to bed"
• Appear in a show, on T. V. Or radio.
  • usage: "The news won't be on tonight"
  • synonyms: be on
• Develop in a positive way.
  • usage: "He progressed well in school"; "My plants are coming along"; "Plans are shaping up"
  • synonyms: progress, come on, come along, advance, get along, shape up
• Grow old or older.
  • usage: "She aged gracefully"; "we age every day-what a depressing thought"; "Young men senesce"
  • synonyms: senesce, age, mature, maturate