5 definitions
First Monday in October (n.) is autumn's ceremony for people who find football too fast.
First Monday in October (n.) is the one Monday the country's biggest arguments all begin on.
First Monday in October (n.) is the Supreme Court's new year, with the resolutions handed out in June.
First Monday in October (n.) is the day nine people return from summer to decide what the rest of us may do.
First Monday in October (n.) is when the Supreme Court comes back and the lower courts hold their breath.