Thingymbob

Usually an item currently in use which you can't be bothered to remember the name of

I'm going to use this thingymbob to break over his head

This is my beautiful thingymbob, we're getting married in 6 months

What-ye-call-it

(Whachjecallit)
A word substituted when the correct noun is spontaneously forgotten

Also known as "on the tip of my tongue" or "f**kin..."

Yea I used the What-ye-call-it to hit the thingymbob into the plank of wood

Yea

When yeah is too long, ye is too short, yes is too formal, enter Yea. The casual, easily typeable, fun, but not haha fun, substitute for yes

Yea bro
Yea I'm down to conquer Albania

Yea that sounds cool