Extreme example of generosity? (3)
I believe the answer is:
tip
'extreme' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for tip that I've seen before include "Extremity; gratuity" , "Gratuity; hint" , "tiny reward" , "present!" , "offered at end of repast" .)