A person who informs on someone else, often to the authorities; an informer or snitch. The gang was wary of squealers who might betray their plans to the police.
A person or animal that makes a high-pitched, shrill sound. The piglet was a noisy squealer, making its presence known throughout the barn.
In livestock farming, a young pig weighing roughly 40 to 80 pounds, especially one that has been recently weaned. The farmer moved the squealers to a separate pen to monitor their growth.