If you are wanting more of an academic definition of globalization, check out the definition given by the Stanford Enyclopedia of Philosophy.
If you are wanting more of a reachable definition, read mine below:
Globalization is about being connected to others, irrespective of one’s geographical location. Globalization is lived out when an individual goes to their supermarket, which is owned by someone from another country, and buys a mango that was imported from Thailand. That individual got to the grocery store by driving in their car, which was assembled in Mexico, while listening to music, playing off their music player designed by a company in Cupertino, California, but which was assembled in China. Since the mango was so delicious, the individual tweets and facebooks, “Thai mangoes are the best!” Afterward, a farmer from Thailand sees that tweet and responds back, “thanks!” This illustration is a glimpse into globalization.
In essence, globalization is the process by which market economies have more of a direct impact on each other, nations develop more of a reliance on one another for resources, individuals from around the world begin speaking the same language, and pollution in one country affects individuals half way around the world. Consequently, the world suddenly seems a lot smaller.
A relatively high level of cultural and technological development; specifically :the stage of cultural development at which writing and the keeping of written records is attained.