Meaning of ACID-BASE INDICATOR

WordNet Dictionary
	Definition:		[n]  an indicator that changes color on going from acidic to basic solutions
	See Also:		bromophenol blue, bromothymol blue, bromphenol blue, bromthymol blue, congo red, indicator, litmus, litmus test, methyl orange, phenolphthalein, tetrabromo-phenolsulfonephthalein