Accurate (adjective)

1. Free from error : exact.
2. Conforming to fact or truth : reliable.

Origin:

Middle english, from latin accuratus, past participle of accurare to make accurate, from ad- + curare to take care of.

Examples:

1. The measurements were accurate to within a millimeter.
2. The watch keeps accurate time.
3. The translation is accurate and idiomatic.
4. The map is not accurate, it is missing some streets.
5. The weather forecast is accurate for the next three days.