The term "in-bred" refers to individuals or animals having common ancestors or being related by blood. The antonyms for "in-bred" are "outbred" or "crossbred." Outbred refers to animals or individuals that do not share any common ancestors, and their lineage is mixed with other unrelated animals or individuals. Crossbred refers to the deliberate breeding of two different species or breeds, resulting in a new breed that is not inbred. In-breeding can lead to genetic defects and diseases, while out-breeding and cross-breeding can result in stronger and healthier offspring. Therefore, it is essential to consider the consequences of in-breeding when breeding animals or marrying relatives.