Yours, Etc.: Origins and Uses of 8 Sign-Offs
1610s, "done with care," from Latin accuratus "prepared with care, exact, elaborate," past participle of accurare "take care of," from ad- "to" (see ad-) + curare "take care of" (see cure). The notion of doing something carefully led to that of being exact (1650s). Related: Accurately; accurateness.