The word "tax" is a Lower Northeast Philadelphia (Roosevelt) slang word that means the following.
1. To engage in sexual intercourse, the act of fornicating.
2. To have a strong liking for something, someone or anything. A ringing endorsement.
Yo, I taxed that party last night.=That party was a great time.
Yo, I taxed that jawn last night.=You either had sex with a woman (jawn), or you really enjoyed something you did last night (jawn)
I tax Johnny.= Johnny is cool as shit.
I tax Veronica.=I have sex with a girl named Veronica.
I taxed that cheesesteak.=That was a good ass cheesesteak