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1. Rebecca Black's "Friday" parody made by Rucka Rucka Ali.

2. A day where you get high as hell. My way of decribing 420.
1. Guy 1: "What's your favorite parody?"
Guy 2: "High Day" by Rucka Rucka.

2. Stoner:"Hurry up, Time!"
Normal guy: "Why?"
Stoner: It's High Day in 3 days."
by omega2900 April 16, 2011
When you use Friday after work to get high and relax after a long week.
"Dude, this week has been brutal at work this week I can't wait for Highday"
by Tenekrassland September 25, 2011