Answer:
What is the freedom of birds and the pen of old men?
Long and think, red within, with a nail at the end.
They can be harbored, but few hold water. You can nurse them, but only by holding them against someone else. You can carry them, but not with your arms. You can bury them, but not in the earth.
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
I scribble forms of the finest letter, And repel elements of the harshest weather. I am an arrow-aimer and a dust-breaker.
As round as an apple. As deep as a cup. All the king's horses can't pull it up.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?