Definition of "accidently"

[T]he exceptions remind me of an ingenious conjecture respecting Newton: that he was probably a being of a superior order, accidently caged in a human body.

1791 (date written), Mary Wollstonecraft, A Vindication of the Rights of Woman: With Strictures on Political and Moral Subjects, 1st American edition, Boston, Mass.: […] Peter Edes for Thomas and Andrews, […], published 1792

As I arrived at the foot of the hill I overtook two ladies, whom I passed. As I did so, I brushed one of them accidently on the arm.

1899, Knut Hamsun, “Part I”, in George Egerton [pseudonym; Mary Chavelita Dunne Bright], transl., Hunger […], London: Leonard Smithers and Co […], page 15

[W]hich arises from four galaxies at four quite different distances that accidently appear close together in the sky. The second line represents two galaxies close together in space and the other two accidently close in projection, the third line close triplets plus a fourth accidently close in projection, the fourth line two close pairs accidently seen close together in projection.

1980, Phillip James Edwin Peebles, The Large-Scale Structure of the Universe (Astrophysics), Princeton University Press, page 151

[R]elayed similar cases but suspected that the rocks were accidently dislodged as the animals fled. […] Hall (1963) considered the same data and concluded that while such behavior might originate accidently during flight or display, […]

2011, Robert W. Shumaker, Kristina R. Walkup, Benjamin B. Beck, Gordon M. Burghardt, Animal Tool Behavior, 2nd edition, JHU Press, page 92

Juan accidently spills some coffee on a client during a business meeting. Juan's tort is clearly in the scope of employment.

2012, Patrick R. Delaney PhD, CPA, O. Ray Whittington, Wiley CPA Exam Review 2012, Regulations, page 334