Possible Clues:

• Definitive or exact
• Clear and exact
• Very particular small exercise to change initially if in charge
• Particular spice if cooked has to get cold
• Investment by independent fellow in charge is precise
• Particular southern sports clubs regularly reversed coin flip
• Clearly-defined brief theorising whenever in command
• Particular rampant mushroom in sci-fi production
• Particular, distinct
• Definite remedy