What does it mean to be “Slippin'”(or Slipping)?
The term and slang “Slippin'” (also spelled Slipping) is a verb.
Slippin' means beings caught off guard or not paying attention.
To be caught slipping is when someone catches you off guard or doing something you shouldn't be doing.
Read: What does “Plug” mean?
Read: What does “Shook” mean?