~Pronounced~
Tac-tic-al -ess-eye

SI is short for 'sick'

If you are tactically sick, you are sick on purpose.

This act was common with the Romans, where they ate a meal, and then threw-up, in order to eat more food.

Nowadays this act is more common in drinking games, where someone is sick to allow more alcohol consumption.
"I needed to Tactical SI to finish that last round up"
by Steven Garfirth August 24, 2008
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