1.n. The once-monthly assembly where departing seniors pass on their "wisdom" to younger students, i.e., spew bullshit for 30 free lunch sign-outs. Occasionaly, someone decides to be funny or rebelious, but usually ends up looking stupid. See also the extremely rare, "HomoSeniorous Speechus," given only when the school is in the theroes of homophobia.
"Shit, it's senior speeches today, and I left my pillow at home."
"Damn, you see that senior speech today? Yeah, that kid Ravi wont shut his damn mouth."