A lengthy lecture on a subject; a treatise; a discourse; a sermon.
A formal exposition of a subject, especially a research paper that students write in order to complete the requirements for a doctoral degree in the US and a non-doctoral degree in the UK; a thesis.
deadly silence
The act of refraining from speaking.
The absence of any sound.
To repress the expression of something.
To suppress criticism, etc.
To block gene expression.
To murder.
To make (someone or something) silent.
Be silent.