Meaning of “stump” - Learner’s Dictionary

stump

verb uk us /stʌmp/
be stumped by sth informal

to not be able to answer a question or solve a problem because it is too difficult:

Scientists are completely stumped by this virus.

[ I ] US to travel to different places to get political support

(Definition of “stump verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)