An Action: whereby a person tells another person what he/she really thinks of them through the medium of speech.
A phrase accredited to Oliver Campbell.
"Oh my god, did you hear, David "Oli'd" Mason.
"RICHARD, YOU DISGUST ME!" Oli, doing an Oli.
"Jean Michel Jarre, you daft bastard." A Geordie person "doing an Oli" to Jean Michel Jarre