showing a negligible or permissible deviation from a standard: an accurate ruler
3.
without error; precise; meticulous
4.
maths
a. (to n significant digits) representing the first n digits of the given number starting with the first nonzero digit, but approximating to the nearest digit in the final position: since π = 3.14159…, the approximation 3.1416 is accurate to 5 significant digits.
b. (to n decimal places) giving the first n digits after the decimal point without further approximation: π = 3.1415 is in this sense accurate to 4 decimal places
[C16: from Latin accūrātus, past participle of accūrāre to perform with care, from cūra care]
1610s, "done with care," from L. accuratus "prepared with care, exact," pp. of accurare "take care of," from ad- "to" + curare "take care of" (see cure). The notion of doing something carefully led to that of being exact (1650s). Related: Accuracy.