shellism

When your sister/anyone creates a new word totally oblivious that word doesn't exist and surrounding party notice straight away.

Shellism; "its on the sharcel pelf"

Innocent victim; "what?"
Shellism; "THE SHARCEL PELF, JEEZ"
Innocent victim; "what the heck is a 'Sharcel Pelf?'"
Shellism; "Oh, um its a parcel shelf"

Mattnip

When a Matt or Matthew goes completely bonkers with 1000% energy and excitement.

Matt finds another pen
"Jeez Matts been on the "Mattnip", hes mentally excited about finding a pen !"