Merriam-Webster's Collegiate® Dictionary, 11th Edition
LOP
I. noun
Etymology: Middle English loppe
Date: 14th century
material cut away from a tree,
II. transitive verb (lopped; lopping)
Date: 1519
1. a. to cut off branches or twigs from, to sever from a woody plant, b. to cut off the head or limbs of, to cut from a person,
2. to remove superfluous parts from, to eliminate as unnecessary or undesirable,
III. intransitive verb (lopped; lopping)
Etymology: perhaps imitative
Date: 1578
to hang downward ; droop