1. To mimic or imitate, esp. in an amusing or satirical manner
2. To prove fatal
3. To remove clothes
4. To take away or remove,
5. To take off from the ground, as of an aircraft or balloon; SYN. lift off.
6. To take time off from work; stop working temporarily; SYN. take time off.
When an airplane leaves the ground and flies up into the air, it takes off.
When a business or other organized activity becomes very successful, it takes off.