Antonyms for the word "re-assurance" include doubt, uncertainty, insecurity, distrust, unbelief, and nervousness. These words represent the absence of the comfort and confidence that reassurance brings. Doubt is the opposite of reassurance's certainty, while uncertainty represents the lack of assurance. Insecurity is the feeling of not being safe or stable, which reassurance can help eliminate. Distrust refers to the inability to trust something or someone, while unbelief represents a lack of faith or trust in something. Lastly, nervousness describes the feeling of worry or anxiety, which reassurance can alleviate. In summary, these antonyms emphasize the importance of reassurance in promoting a sense of security and confidence.