Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun congo_red

1 sense of congo red

Sense 1
congo red -- (a red-brown azo dye especially as a chemical pH indicator (congo red is red in basic and blue in acidic solutions))
       => azo dye -- (any dye containing one or more azo groups)
       => acid-base indicator -- (an indicator that changes color on going from acidic to basic solutions)