Does not mean cereal, or anything even close to it. It does not mean serious, in fact it doesn't even exist, not even in slang. Please learn how to spell, and stop making stuff up, it really is just embarrassing.
"Mmmm this cereal is good"
"Nah son dat ceral is good"
"Shut up retard, just quit now"
1.Something losers kill themselves in
2.to be serious about something
food that will cheer up a cnadise or samanth