Answer:
What is a five-letter word that has brain in it?
It doesn't live within a house, nor does it live without. Most will use it when they come in, and again when they go out.
A house with two occupants, sometimes one, rarely three. Break the walls, eat the boarders, then throw away me.
The sharp slim blade, that cuts the wind.
Just head and foot yet never tires of dancing.
I have two eyes in the front and a lot of eyes on my tail