noun The state of being precise or exact; especially, both exact and accurate.
noun The ability of a measurement to be reproduced consistently.
The classic example of the difference between precision and accuracy is that in target practice, if the grouping is tight but the group is off-center, your precision is good but your accuracy needs calibration.
noun The number of significant digits to which a value may be measured reliably.
noun A bidding system that makes use of many artificial bids to describe a hand quite precisely.