Knives, swords, razors, and human shoulders all have one

Hidden deep within sections of text, the answer waits. What word is hidden?

I have something and you reeeeeeeeally want it. I take two letters to say, but four to spell. You won't be satisfied until you have what I have, but in truth, the feeling won't quit It's a feeling that you'll likely never quell

In the barnyard, you'll find me among the straw, an older tool with pointed claw, helping gather what the farmer did sow, Or, paired with a torch, scaring off some common foes

Is this tennis? Is this noise? I don't know, you tell me what my identity is!