A response to a stimulus

An emotional response

एक भावनात्मक प्रतिक्रिया

English Usage: Her reaction to the news was one of shock.

Hindi Usage: समाचार पर उसकी प्रतिक्रिया सदमे की थी।

Not finished or whole

Lacking a part

एक भाग की कमी

English Usage: His understanding of the topic was incomplete.

Hindi Usage: विषय की उसकी समझ अधूरी थी।