Answer:
I know a word of letters three. Add two, and fewer there will be!
I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back. None suffer to have me, but do from my lack.
Just head and foot yet never tires of dancing.
This is needed both for courage and hardcover books.
What’s black in the morning, red in the afternoon, and white at night?
People take me on walks and I run and have fun. What am I?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?