Of force sufficient to fell or completely overthrow; as, a knockdown blow; a knockdown argument..

Of or pertaining to the act of knocking down at an auction; specif., designating the price below which an article will not be disposed by the auctioneer.

Made or constructed so as to be capable of being knocked down or taken apart, as for transportation.

Anything that causes an enemy to be knocked down on the ground, disrupting their offensive moves, and leaving them open for further abuse. LFG: Looking For Group is the key phrase when looking for other members to group up with. This can be preceded by a class and level to aid those LFM, e.g., "LvL 18 Monk LFG."

Call on the golf gods to help you pull off this shot when you need to get under tree limbs or keep your ball down out of the wind. Starting with the ball way back in your stance and finishing with an abbreviated follow-through should result in the knockdown shot.

If you don’t want to do the traditional "Orange Peel" splatter, another option is knockdown textures. The term "knockdown" comes from the technique used to knock the top of the splatter down for a unique look.

a blow that knocks the opponent off his feet

An obstacle is considered knocked down when a horse or rider, by contact, lowers any element which establishes the height of an obstacle. Interestingly, should the horse dislodge an element of the jump, as a result, does not lower the height of the jump, no jumping faults will be incurred.

Splatter texture applied to a surface that is then troweled to achieve a particular finish.  Normally used to describe finish on drywall interior walls and ceilings, porch and pool deck floor finishes, as well as a particular type of exterior wall stucco finish.