Real Dictionary

take on
If something takes on a new appearance or quality, it develops that appearance or quality.
If you take someone on, you fight them or compete against them, especially when they are bigger or more powerful than you are.
phrasal verb: If a vehicle such as a bus or ship takes on passengers, goods, or fuel, it stops in order to allow them to get on or to be loaded on.
phrasal verb: If you take on a job or responsibility, especially a difficult one, you accept it.
phrasal verb: If you take someone on, you employ them to do a job.

take on in American English
to acquire; assume (form, quality, etc.)
to hire; employ

take on in British English
to employ or hire