Chunk

From DwarfFortressWiki

A chunk of any type is a waste object generated either by butchering animals or by fierce combat. Chunks have no in-game use and are considered refuse.

When a creature is biting another and has a body part grasped in its mouth, chunks of the body part can get ripped away, worsening the wound. Sometimes the entire body part will remain in its mouth as it is torn away, depending on the health of it and the size. On major body parts, if too many chunks get ripped away, the wound could become instantly fatal, if not the parts ripped away by the creature's grip.

Chunks will rot fairly quickly and produce miasma, so ensure that you have enough refuse space (or dumping space) to account for this.