Question

What is the definition of self-indicating?

Answer 1

Self-Indicating mean telling about own presence in Chemistry Potassium Permenganate KMnO4 is used as self-indicator in a solution.
Potassium Permenganate KMnO4 is used as a titrant and its color is dark purple, as the end point of solution is reached KMnO4 is in excess and solution gains dark purple color permanently which indicates presence of KMNO4 in the solution.

Answer 2

Self indicating or self indicator is the substance which marks the end point of titration either by precipitation or by changing its color.
examples are 
Methyl Orange
Phenolphtalein
these two are commonly used self indicator in acid base titration .