The act of flushing the toilet halfway through your business, usually done as an act of caution to avoid clogging when using gratuitous amounts of toilet paper.
The time at night when it's no longer safe to make noise in case you don't want to wake anyone up
"I had to take a piss but it was after flush time so I couldn't flush"
"I wanted to get a midnight snack but I couldn't hear up anything in the microwave because it was after flush time