Security plonker Share definition Flag Socially retarded, untrained, Unintelligent, unattractive person often employed to work an unnecessary position. Look at that security plonker over there, hasnt done an ounce of work all day! Security plonker by Locnes November 14, 2016 0 0 Get merch Get the Security plonker mug. Buy Now — $32.95 See more merch