Overdemonstrative refers to someone who is excessively expressive or theatrical when expressing their emotions or feelings. Some synonyms for overdemonstrative could be: overly dramatic, melodramatic, theatrical, exaggerated, flamboyant, theatrical, extravagant, hammy, showy, affected, ostentatious, and grandiose. These terms describe a person who tends to overstate or dramatize their feelings to the point where it seems insincere or over-the-top. While it's important to express emotions, being overly demonstrative can be off-putting, and may make others hesitant to take the person seriously. It's good to strike a balance between expressing emotions in a healthy manner and not being too excessive or theatrical about it.