Almost any penis, but not a very small one.
A foolish person.
A big wet kiss.
Almost anything that is remarkably big.
Almost certainly most derive from plonker as size, but this in turn possibly from "to plonk", to place with little or no accuracy possibly because it was big and heavy. See also plonka
"Put your plonker away, Eric."
"Oh Bob, you're such a plonker."
"When I said she looked nice, she gave me a plonker straight on the lips."
"It was the biggest turkey we'd ever had. A real plonker."
"She plonked the meal down in front of me. 'Get stuck in,' she cried."
What you call someone who is so drunk that his head hits the table and makes a loud "Plonk!"
Ingrid is such a plonker! She is smashed out of her mind!
To be so drunk you're unable to remember the meaning of certain words.
Gerry: You were fairly hammered last night.
Keith: I was off me bleedin plonker I was!!!!!!! Yeeoooww!!!!
Someone whose words are not worth reading.
See also plonk
"Sheesh, what a plonker, I just forwarded all mail from him to the bit bucket
To be extremely drunk.
Gerry: Man, you were hammered last night.
Keith: I know, I was outta me bleedin plonker I was!!!! Yeoooww!!!
Chiefly British: A male paedophile (pedophile) - likes sexual activity with underage boys.
When I was twelve I was walking my bike in the park when this plonker came up to me said I had lovely legs, did I want to go with him. I got on my bike and took off! (This really happened!)
Person of Little Or No Knowledge and Electrical Retarded
Ever got an Electrical shock because of sheer stupidty,therefore you are a PLONKER