accurate

Accurate means exactly right, down to the details — no errors, nothing off. An accurate clock gives the real time to the second; an accurate description of a stranger would let you pick that stranger out of a crowd.

It sits beside precise, and the difference earns its keep. Accurate means close to the truth; precise means finely detailed. A scale that reads 4.0002 kg for a one-kilo weight is precise and not accurate. The noun is accuracy, the adverb accurately, and the negative is inaccurate — unaccurate does not exist. You use it about measurements, accounts, translations, forecasts, maps and memories: things that either match reality or do not. It does not describe a person's character, so an accurate colleague is wrong; the word you want there is careful, or meticulous.