I've got a three year old. He likes to make up words. Here is a sampling of The Dictionary According to Cyrus:
appy
pronunciation: \ap-pee\
Function: noun
1: the fleshy usually rounded red, yellow, or green edible pome fruit of a usually cultivated tree (genus Malus) of the rose family ; also : an appy tree
banana
pronunciation: \ba-naw-naw\ (ba as in bat)
Function: noun
1: an elongated usually tapering tropical fruit with soft pulpy flesh enclosed in a soft usually yellow rind; esecially fun to smash between fingers and smear on the sofa.
diggely heart
pronunciation: \digg-ell-ee hart\
Function: noun
1: it's like a firetruck. It goes fast, and spins around. And it's RED. "I have a diggely heart."
fooey
pronunciation: \foo-ee\
Function: noun
1: nickname for big brother, Forest.
gollo
pronunciation: \go-lo\
Function: noun
1: "No gollo's allowed."
poopt
pronunciation: \poopt\
Function: verb
1: "I go poopt! Somebody wipe my butt!"
pitotos
pronunciation: \pee-to-toz\
Function: pl. noun
1: an erect South American herb (Solanum tuberosum) of the nightshade family widely cultivated for its edible starchy tuber. Usually served at breakfast around here. NOT to be served with salad. "Or brains!"
scromp
pronunciation: \skromp\
Function: verb
1: To press garlic in a garlic press. "Let me scromp it!"
shing
pronunciation: \sheeng\
Function: verb
1: To maim with a sword, equally acceptable for pirates or ninjas. "Fooey! Watch out! I'm gonna shing you!"
snissors
pronunciation: \sniz-zerz\
Function: noun
1: a cutting instrument having two blades whose cutting edges slide past each other. "May I snip this ($100 bill) with my snissors?" (it's already in ten pieces.)
squollo
pronunciation: \skwo-lo\
Function: noun
1: any of various small or medium-sized rodents (family Sciuridae, the squollo family): as a: any of numerous New or Old World arboreal forms having a long bushy tail and strong hind legs. "Mom! Call me Sandy Squollo! Say, Hi Sandy."
wollode
pronunciation: \wol-lod\
Function: noun
1: "Aliens are going to take over the wollode!"
yesternight
pronunciation: \yester-nite\
Function: adverb
1: Very similar to "last night" with the exception that it could be any night in the past. Including one or two years ago. "I sleeped good yesternight"
yestertime
pronunciation: \yester-tym\
Function: adverb
1 : on any day in the past or future : on any day preceding, or following today, and sometimes a day that never existed.
2 : at a time not long past or in the future, or in the imagination : only a short time ago <I wasn't born yestertime> or a while from now <let's have watermelon for lunch yestertime>or in your dreams, man <Mom, remember yestertime when that dragon that blew hot fire on my train and it 'sploded?>
— yestertime adjective
zoop
pronunciation: \zoop\
Function: verb
1: To run a fingernail from heel to toe on the sole of the foot, in an effort to cause sleepiness. "Mom, I tired. Please zoop my toes."