In British English it can mean dim witted. In American English it mostly refers to the girth of something, perhaps a steak. In American slang, thick is an adjective used to describe a woman who has meat on her bones in all the right places, specifically the bootay.
A couple days ago Ms. K and I were crossing Bedford Avenue just as a man rode up on a bicycle. He slowed down as we approached, which I initially thought was because he didn't want to run us over. But then he opened his mouth to speak.
"Ladies, can I ask you a question?"
Crap. Normally I don't engage weird bike riding strangers in conversation, especially since I had a good idea about his angle, but I hoped that perhaps he was lost and was looking for some friendly directions.
"Uh, yeah," I responded as he looked directly at me.
"Is your thick friend single?"
For a moment I was confused . . . and possibly offended as a woman generally never wants to hear herself described as thick. But then I remembered that in some circles thick is a complement. Was he referring to Ms. K? Probably not as she is a little thing and I'm the one with the badonkadonk.
I laughed nervously and answered, "No, I'm not single."
He looked disappointed. "Lucky guy," he said before riding away.
We walked off and laughed off the encounter. I playfully punched Ms. K in the arm. "Hey honey, you're a lucky guy."
But I'm the gay lady that attracts weird guys. Or on the subway. Or at the car wash. Or in cabs.