Barb

The word barb can have many meanings:

• A backward-facing point on a fishhook, arrowhead, or similar implement, rendering extraction from the victim's flesh more difficult. (This is perhaps the most common meaning.)
• A mean-spirited or spiteful remark, probably euphemistically named after the sharp object.
• A breed of dog, also known as the Australian Kelpie
• Several species of fish, in particular those of genus Barbus
• A breed of horse from North Africa.