"WSP" in Snapchat stands for "what's up?" It is an informal, casual greeting used to ask how someone is doing or what they are currently up to. This abbreviation is common in texting and social media messaging apps like Snapchat, WhatsApp, and Instagram. When someone sends "WSP," they are essentially starting a conversation or checking in, similar to saying "hey, what's going on?" or "how are you?"

The term originated from the informal pronunciation of "what's up" as "wassup," popularized by a Budweiser commercial in the late 1990s. While "WSP" can have other meanings in different contexts (such as WhatsApp, web service provider, or white skin privilege), in Snapchat and casual online chats, it almost always means "what's up?"

You can respond to "WSP" with a brief update or a casual reply like "not much," "just chilling," or "busy with work," depending on your relationship with the sender and the context of the conversation.