The Collaborative International Dictionary
Countercheck \Coun`ter*check"\ (koun`t?r-ch?k"), v. t. [imp. & p. p. Counterchecked (-ch?ckt"); p. pr. & vb. n. Counterchecking.] To oppose or check by some obstacle; to check by a return check.
Wiktionary
vb. (en-past of: countercheck)
Usage examples of "counterchecked".
Twenty-odd years of endless Lunar data, done by atomic (cesium) clock, electrically-automatically timed occultations of stars, backed by both triangulation and radar ranging, counterchecked by similar work done on the inner planets by other astronomers at other observatories—Certainly he could be wrong .
They questioned him and counterchecked his answers so often and so thoroughly that when they finally let him go he no longer really felt that the mission had been part of his life.
Theory after theory was advanced and checked and counterchecked and modified and abandoned and revived and converted to something else.