Based on the search results, "blk" can refer to two different things:

1. BLK Dating App: BLK is a dating app designed for Black single men and women. The app aims to create an exclusive community where Black people can find meaningful connections with others who share similar interests. Users can scroll through a personalized list of profiles and swipe right to show interest or left to pass. If two users swipe right on each others profiles, they can start chatting in the app. BLK is only available in the United States and Canada.

2. blk. Functional Beverages: blk. is a brand of functional beverages that are infused with fulvic and humic acid. These minerals give the drinks their dark color and are believed to aid in removing toxins from the body. The beverages also contain electrolytes, antioxidants, and other minerals to promote health and wellness.

In summary, "blk" can refer to a dating app for Black singles or a brand of functional beverages infused with minerals.