What does spanish word pon mean?

Depends on the context:

"Put" (affirmative informal usage only) It is a form of the Word "to put" Poner.

Put your name here. > Pon tu nómbre aquí. (formal) Ponga su nómbre aquí.

It could also be a slang for getting a ride from some one or hitchhiking. In this case it's a noun. You get or grab "pon". Though this term was used widely in Puerto Rico in the 1960s-1980s it may have fallen out of favor and the term was not universal.

I was able to hitch a ride > Conseguí pon