If you say something declamatory, it's full of passion and bluster, like your declamatory speech in debate club about the poor nutritional quality of your school's lunches.
Things that are declamatory are strongly felt and expressed with intensity, and they're usually spoken aloud (and loudly). Sometimes this adjective has negative connotations, implying bluster and bombast: "Your essay is so long and declamatory, I felt like I was being shouted at by a showoff." Something declamatory can be called a declamation. The Latin root, declamare, means "to practice public speaking."