Etymology From Middle English loppe (“bough”); the verb is a back-formation from the noun.
1
Usually, With off To cut off as the top or extreme part of anything, especially to prune a small limb off a shrub or tree, or sometimes to behead someone.
Some, for hard masters, broken under arms, In battle lopt away, with half their limbs, Beg bitter bread thro’ realms their valour sav’d,1742, Edward Young, The Complaint: or Night-Thoughts on Life, Death & Immortality, Night I:
2
To hang downward; to be pendent; to lean to one side.
Etymology From Middle English loppe (“bough”); the verb is a back-formation from the noun.
1
That which is lopped from anything, such as branches from a tree.
Why, we take, From every tree, lop, bark, and part o'the timber1613 (date written), William Shakespeare, [John Fletcher], “The Famous History of the Life of King Henry the Eight”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act I, scene ii]:
I ſhall not trouble you about the raiſing of them of Truncheons or Lops, because I could never find them to take; only ſometimes ſome of the ſmallest Suckers, when the Sap is newly ſtirring in them, if they are ſlipt off from the Tree, will grow1707, J[ohn] Mortimer, The Whole Art of Husbandry; or, The Way of Managing and Improving of Land. […], London: […] J[ohn] H[umphreys] for H[enry] Mortlock […], and J[onathan] Robinson […], →OCLC:
Etymology From Middle English loppe (“flea, spider”), from Old English loppe (“spider, silk-worm, flea”), from Proto-Germanic *luppǭ (“flea, sandflea", originally, "jumper”), from Proto-Germanic *luppijaną (“to jump, dart”). Cognate with Danish loppe (“flea”), Swedish loppa (“flea”). Compare also Middle High German lüpfen, lupfen (“to raise”, obsolete also “to rise”).
US, Dated, Slang (usually offensive) A disabled person, a cripple.
"He's a lop; it mentions here about his getting up to the stand with his crippled leg but it doesn't say which one."1935, Rex Stout, The League of Frightened Men, page 5:
2
Any of several breeds of rabbits whose ears lie flat.