Overwhelm/ˌəʊvərˈwelm/ Definition 1 of 3Pro Tip 1/3Emotional Impact Used when feelings are so strong that one feels unable to react or respond. Seeing their reunion after years overwhelmed him with happiness. Pro Tip 2/3Unexpected Intensity Often describes a sudden and intense feeling that catches someone off guard. The surprise party overwhelmed her; she couldn't stop crying. Pro Tip 3/3Positive or Negative Can refer to both good and bad emotions. Overwhelmed with relief, he thanked his rescuers profusely.