Steap is a creative variation of the word "steep" which is commonly associated with the process of making tea.
To prepare chrysanthemum tea, steap flower in hot water for several minutes and pour into your favourite cup
When you have tea, but you’re letting it sit. Keeping the information to yourself for the moment
Me: hey, Caleb, got any tea?
Caleb: yeah, but it’s sTEAping right now.
Deep in thought, contemplating, considering.
Abel: what are you sTEAping about?
Cain: oh nothing...