v. Simple past tense and past participle of overtop.
The Century Dictionary and Cyclopedia
In forestry, having the crown shaded from above, although a side or sides may be free to light. See crown class.
Word Usage
"This supports the administration's contention that the White House was receiving conflicting reports during the course of Aug. 29 about whether the levees had been breached or simply "overtopped" by hurricane-driven flood waters."