Определение drill instructor в Английский Язык Английский Язык словарь
The generic term for the principal instructor of fresh military recruits undergoing basic training in the various branches of the United States military, routinely abbreviated to the initialism DI; always filled by enlisted personnel (a sergeant or petty officer)
Coast Guard: company commander.
a noncommissioned officer who instructs recruits in military marching and discipline
A noncommissioned officer who instructs recruits in military drill and discipline