What is the meaning of the word "push"?

Definitions:

an effort to advance noun
- the army made a push toward the sea
an electrical switch operated by pressing noun
- the elevator was operated by push buttons
approach a certain age or speed verb
- We were pushing eighty on the highway when we saw police lights in the rearview mirror.
make strenuous pushing movements during birth to expel the baby verb
- `Now push hard,' said the doctor to the woman
move strenuously and with effort verb
- The crowd pushed forward
press against forcefully without moving verb
- I pushed against the wall with all my strength.
press, drive, or impel someone to action verb
- My advisor pushed me to finish my doctorate.
sell or promote the sale of illegal goods such as drugs verb
- The person hanging around the school is pushing drugs.
the act of applying force in order to move something away noun
- When we ran out of gas, we had to push our car to the nearest gas station.
the force used in pushing noun
- the push of the water on the walls of the tank