A very small amount compared to what is needed or expected.

नगण्य / अत्यल्प मात्रा

English Usage: The $100 donation was just a drop in the bucket compared to the millions needed for the renovation.

Hindi Usage: मरम्मत के लिए लाखों की आवश्यकता थी, उसमें $100 का दान केवल नगण्य मात्रा था।