Answer:
The distance from the top of your head to the floor standing up straight.
Other terms for this handy device include doohicky, doo-dad, and whatchyamacallit.
The profession of Jimi Hendrix and Eric Clapton
Inside a burning house, this thing is best to make. And best to make it quickly, before the fire's too much to take.
I occur twice in eternity. And I'm always within sight.
It is something you will never see again.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?